…lay (#921)

As described in the [upstream deck.gl
docs](https://deck.gl/docs/developer-guide/base-maps/using-with-maplibre),
there are three ways to support using deck.gl with Maplibre:
_interleaved_, _overlaid_, and _reverse-controlled_. The first two are
supported via `MapboxOverlay` with a prop `interleaved: true|false`,
while the latter is implemented by having Maplibre be a child of the
deck.gl Map.

There are worthwhile reasons to support all of these modes. We need to
use interleaved or overlaid to support globe view, while
reverse-controlled better supports multiple deck.gl views.

This PR refactors the map component in `index.tsx` into two separate
React components: a deck.gl-first renderer (i.e. "reverse-controlled")
and a MapboxOverlay renderer.

The idea is that this will pair with #908 to give users more control
over various ways of rendering maps.

This is backwards-compatible because we default to reverse-controlled,
the existing default.

Closes #890, closes
#437, for
#886, for
#718

A small refactor to make it easier to read `_map.py` by removing the
HTML export functionality, moving that to `_html_export.py`. This was
extracted from #908, see
https://github.com/developmentseed/lonboard/pull/908/files#r2414276602

…ap` if no value of `basemap` was passed. (#963)

Extracted from #908 so
that `main` is clear

### Change list

- Adds definitions for map "controls" (which deck.gl calls "widgets",
but the name "widget" is too overloaded in the context of Jupyter, so
I'd like to call them "controls")
- Support for `ScaleControl`, `NavigationControl`, `FullscreenControl`
- These controls are supported by both deck.gl and maplibre, and so
implementations are defined for creating both the deck.gl and maplibre
counterparts

### Example

```py
from lonboard import Map
from lonboard.controls import ScaleControl, FullscreenControl, NavigationControl
from lonboard.basemap import MaplibreBasemap

m = Map([], 
    basemap=MaplibreBasemap(mode="overlaid"),
    controls=[ScaleControl(), FullscreenControl(), NavigationControl()]
)
m
```

<img width="734" height="506" alt="image"
src="https://github.com/user-attachments/assets/42fb5e55-57d8-4b2a-8fe2-f70b804dabce"
/>

We should probably change the default positioning of controls, move the
bbox selector, or make the bbox selector a control itself.

----

However, for deck.gl-driven rendering, I can only see the scale control:
<img width="756" height="611" alt="image"
src="https://github.com/user-attachments/assets/f8e6be57-55ec-45be-9c14-cf76b4ea64d0"
/>

Logged in #990

### Todo list

- Figure out how to pass these react components as children of the
`OverlayRenderer` or `DeckFirstRenderer` (depends on
#921)
- Use the refactored model initialization from
#923 to create the list
of control instances on the deck side
- Integrate more cleanly into the Python API (an extension of
#908)

Closes #842, relevant
to #681