Refactor form building

[martinRenou]

Generalize the form building logic.

This PR provides two types of React forms:

• creation form: Allows to create a layer and a source at once or just one or the other
• edit form: Allows to edit a layer and a source at once or just one or the other

These react forms are used in multiple places of the UI (dialogs, gallery, right panel)

Specializing edit/create UI requires providing a custom form class inheriting from BaseForm

[github-actions]

👈 Launch a Binder on branch martinRenou/jupytergis/refactor_form_building

[brichet]

Thanks @martinRenou, huge changes, and it works well.

I have a few comments below, otherwise let's fix the tests and move forward.

For the record, we should also update the createGeoJSONSource() and createVectorLayer() functions, which do not use this new form builder.

[martinRenou]

please update snapshots!

[martinRenou]

I commented out the test for #66

[brichet]

Thanks @martinRenou for the update (and the rework of geojson source creation)

[brichet]

Is there a known reason for this update ?

[martinRenou]

This is due to CSS changes in #48

[brichet]

Maybe we should use a versioned version of the map if it exists.

[martinRenou]

Indeed, that's a good idea. If that exists for one provider we should use it for testing.

[martinRenou]

Thanks!