Faster storage chunk iteration

[macneale4]

Currently we have two access patterns where we need to iterate over all chunks in a storage file: Archive/Unarchive and FSCK. In both cases, we are loading one chunk at a time and disk IO becomes a bottleneck. This change updates the iteration methods to iterate over the data blocks of table files and archive files such that we can load data in larger batches.

There are not new tests for this. archive and fsck tests should cover this.

Testing on a 500Mb database: 8.7s to fsck before change, 5.0s after change.

[coffeegoddd]

@macneale4 DOLT

comparing_percentages
100.000000 to 100.000000

version	result	total
25aba8f	ok	5937457

version	total_tests
25aba8f	5937457

correctness_percentage
100.0

[coffeegoddd]

@coffeegoddd DOLT

comparing_percentages
100.000000 to 100.000000

version	result	total
fe25b3d	ok	5937457

version	total_tests
fe25b3d	5937457

correctness_percentage
100.0

[coffeegoddd]

@macneale4 DOLT

comparing_percentages
100.000000 to 100.000000

version	result	total
1193ca1	ok	5937457

version	total_tests
1193ca1	5937457

correctness_percentage
100.0

[coffeegoddd]

@coffeegoddd DOLT

comparing_percentages
100.000000 to 100.000000

version	result	total
2e9851a	ok	5937457

version	total_tests
2e9851a	5937457

correctness_percentage
100.0

[coffeegoddd]

@macneale4 DOLT

comparing_percentages
100.000000 to 100.000000

version	result	total
535c415	ok	5937457

version	total_tests
535c415	5937457

correctness_percentage
100.0

[coffeegoddd]

@coffeegoddd DOLT

comparing_percentages
100.000000 to 100.000000

version	result	total
365656d	ok	5937457

version	total_tests
365656d	5937457

correctness_percentage
100.0

[coffeegoddd]

@macneale4 DOLT

comparing_percentages
100.000000 to 100.000000

version	result	total
389748b	ok	5937457

version	total_tests
389748b	5937457

correctness_percentage
100.0

[reltuk]

Given the structure of these files, I think it makes more sense to put the chunk readers through bufio than to try to roll our own with the outer loop and tracking offset, etc.

#9515

[coffeegoddd]

@macneale4 DOLT

comparing_percentages
100.000000 to 100.000000

version	result	total
e683779	ok	5937457

version	total_tests
e683779	5937457

correctness_percentage
100.0

[coffeegoddd]

@macneale4 DOLT

comparing_percentages
100.000000 to 100.000000

version	result	total
e04c46c	ok	5937457

version	total_tests
e04c46c	5937457

correctness_percentage
100.0