gh-36666: Replace relative imports by absolute ones in `sage.{algebras,arith,categories,cpython,data_structures,misc,modular,rings,sat,symbolic}`
    
<!-- ^^^^^
Please provide a concise, informative and self-explanatory title.
Don't put issue numbers in there, do this in the PR body below.
For example, instead of "Fixes #1234" use "Introduce new method to
calculate 1+1"
-->
<!-- Describe your changes here in detail -->

<!-- Why is this change required? What problem does it solve? -->
Final chunk of the cherry-pick from #35095 for #36228, see also
#36572 (comment)

This PR overlaps with #36572, #36588, #36589, but it does not touch
`.all*` files (no changes there are needed for #36228), thus avoiding
conflicts with #35095 (see also
#36524 (comment))
<!-- If this PR resolves an open issue, please link to it here. For
example "Fixes #12345". -->
<!-- If your change requires a documentation PR, please link it
appropriately. -->

### 📝 Checklist

<!-- Put an `x` in all the boxes that apply. -->
<!-- If your change requires a documentation PR, please link it
appropriately -->
<!-- If you're unsure about any of these, don't hesitate to ask. We're
here to help! -->
<!-- Feel free to remove irrelevant items. -->

- [x] The title is concise, informative, and self-explanatory.
- [ ] The description explains in detail what this PR is about.
- [x] I have linked a relevant issue or discussion.
- [ ] I have created tests covering the changes.
- [ ] I have updated the documentation accordingly.

### ⌛ Dependencies

<!-- List all open PRs that this PR logically depends on
- #12345: short description why this is a dependency
- #34567: ...
-->

<!-- If you're unsure about any of these, don't hesitate to ask. We're
here to help! -->
    
URL: #36666
Reported by: Matthias Köppe
Reviewer(s): David Coudert, John H. Palmieri

Author: Release Manager

src/sage/algebras/quatalg/quaternion_algebra_cython.pyx

@@ -35,7 +35,7 @@ from sage.matrix.matrix_space import MatrixSpace
 from sage.matrix.matrix_integer_dense cimport Matrix_integer_dense
 from sage.matrix.matrix_rational_dense cimport Matrix_rational_dense
 
-from .quaternion_algebra_element cimport QuaternionAlgebraElement_rational_field
+from sage.algebras.quatalg.quaternion_algebra_element cimport QuaternionAlgebraElement_rational_field
 
 from sage.libs.gmp.mpz cimport mpz_t, mpz_lcm, mpz_init, mpz_set, mpz_clear, mpz_init_set, mpz_mul, mpz_fdiv_q, mpz_cmp_si
 

src/sage/categories/action.pyx

@@ -91,7 +91,7 @@ cdef class Action(Functor):
       :class:`Action` itself, but other classes may use it
     """
     def __init__(self, G, S, is_left=True, op=None):
-        from .groupoid import Groupoid
+        from sage.categories.groupoid import Groupoid
         Functor.__init__(self, Groupoid(G), category(S))
         self.G = G
         self.US = ref(S)

src/sage/categories/morphism.pyx

@@ -467,7 +467,7 @@ cdef class CallMorphism(Morphism):
 cdef class IdentityMorphism(Morphism):
 
     def __init__(self, parent):
-        from .homset import Homset, Hom
+        from sage.categories.homset import Homset, Hom
         if not isinstance(parent, Homset):
             parent = Hom(parent, parent)
         Morphism.__init__(self, parent)

src/sage/cpython/getattr.pyx

@@ -4,7 +4,7 @@ Variants of getattr()
 
 from cpython.object cimport PyObject, PyTypeObject, Py_TYPE, descrgetfunc
 
-from .string cimport bytes_to_str
+from sage.cpython.string cimport bytes_to_str
 
 cdef extern from "Python.h":
     r"""

src/sage/cpython/wrapperdescr.pyx

@@ -30,7 +30,7 @@ Pure Python classes have normal methods, not slot wrappers::
 #                  https://www.gnu.org/licenses/
 # ****************************************************************************
 
-from .string import bytes_to_str
+from sage.cpython.string import bytes_to_str
 
 
 def wrapperdescr_call(slotwrapper, self, *args, **kwds):

src/sage/misc/cachefunc.pxd

@@ -1,4 +1,4 @@
-from .function_mangling cimport ArgumentFixer
+from sage.misc.function_mangling cimport ArgumentFixer
 
 cpdef dict_key(o) noexcept
 cpdef cache_key(o) noexcept

src/sage/misc/lazy_import.pyx

@@ -66,7 +66,7 @@ import os
 import pickle
 from warnings import warn
 import inspect
-from . import sageinspect
+from sage.misc import sageinspect
 
 
 # LazyImport.__repr__ uses try... except FeatureNotPresentError.
@@ -1137,7 +1137,7 @@ def save_cache_file():
         sage: sage.misc.lazy_import.save_cache_file()
     """
     from sage.misc.temporary_file import atomic_write
-    from .lazy_import_cache import get_cache_file
+    from sage.misc.lazy_import_cache import get_cache_file
 
     global star_imports
     if star_imports is None:
@@ -1180,7 +1180,7 @@ def get_star_imports(module_name):
     """
     global star_imports
     if star_imports is None:
-        from .lazy_import_cache import get_cache_file
+        from sage.misc.lazy_import_cache import get_cache_file
         star_imports = {}
         try:
             with open(get_cache_file(), "rb") as cache_file:

src/sage/misc/persist.pyx

@@ -42,7 +42,7 @@ import bz2
 comp = zlib
 comp_other = bz2
 
-from .sage_unittest import TestSuite
+from sage.misc.sage_unittest import TestSuite
 
 
 # We define two global dictionaries `already_pickled` and
@@ -1237,7 +1237,7 @@ def db(name):
 
     The database directory is ``$HOME/.sage/db``.
     """
-    from .misc import SAGE_DB
+    from sage.misc.misc import SAGE_DB
     return load('%s/%s'%(SAGE_DB,name))
 
 
@@ -1250,5 +1250,5 @@ def db_save(x, name=None):
     try:
         x.db(name)
     except AttributeError:
-        from .misc import SAGE_DB
+        from sage.misc.misc import SAGE_DB
         save(x, '%s/%s'%(SAGE_DB,name))

src/sage/misc/sage_timeit_class.pyx

@@ -6,7 +6,7 @@ The ``timeit`` command
 This uses the function :func:`~sage.misc.sage_timeit.sage_timeit`.
 """
 
-from . import sage_timeit
+from sage.misc import sage_timeit
 
 
 class SageTimeit:

src/sage/modular/modsym/heilbronn.pyx

@@ -34,11 +34,11 @@ cdef extern from "<math.h>":
     float roundf(float x)
 
 cimport sage.modular.modsym.p1list as p1list
-from . import p1list
+from sage.modular.modsym import p1list
 cdef p1list.export export
 export = p1list.export()
 
-from .apply cimport Apply
+from sage.modular.modsym.apply cimport Apply
 cdef Apply PolyApply= Apply()
 
 from sage.matrix.matrix_rational_dense cimport Matrix_rational_dense