Have multiple ways to create layers external file sources

[martinRenou]

Requires #246

When showing up the creation forms for these sources (GeoJSON, GeoTIFF, ShapeFile etc), we should show:

• an input box to allow URLs
• and FileUpload input to allow uploading from user machine
• a button that opens a JupyterLab filebrowser to access server files

[martinRenou]

Drag and dropping a file on the map should also automatically upload and create the layer

[mfisher87]

Drag and dropping a file on the map should also automatically upload and create the layer

💯

[gjmooney]

Drag and dropping a file on the map should also automatically upload and create the layer

This used to work with geojson files.

[martinRenou]

Oh I didn't see that! Do you have a reference to the PR adding this ?

[gjmooney]

#112 according to gitlens 🤷 . It's at https://github.com/geojupyter/jupytergis/blob/main/packages/base/src/mainview/mainView.tsx#L178

[martinRenou]

Nice! Then let's apply this to all layers for which it makes sense