Color relief support and hillshading improvements. (#1371)

## Launch Checklist

This adds support for `relief-color` property so that it will create an
elevation expression when the button is pressed.
It also adds support for `colorArray` and `numberArray` types so that
the user would be able to add the relevant information.

Before:
<img width="403" height="324" alt="image"
src="https://github.com/user-attachments/assets/250abd81-6176-4711-a1ee-d33d443932d7"
/>

<img width="403" height="324" alt="image"
src="https://github.com/user-attachments/assets/6a1bb268-66db-42a1-97fc-33e5a40863b6"
/>


After:
<img width="403" height="324" alt="image"
src="https://github.com/user-attachments/assets/8ebaa1ea-4ef9-4aed-abcd-3c8b0057ea76"
/>

<img width="403" height="324" alt="image"
src="https://github.com/user-attachments/assets/e0728c92-85f9-4b86-8635-8877cf257b2f"
/>


 - [x] Briefly describe the changes in this PR.
- [x] Include before/after visuals or gifs if this PR includes visual
changes.
 - [x] Write tests for all new functionality.
 - [x] Add an entry to `CHANGELOG.md` under the `## main` section.

---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

src/locales/it/translation.json

@@ -16,6 +16,7 @@
   "Delete expression": "Elimina espressione",
   "Convert property into a zoom function": "Converti proprietà in una funzione di zoom",
   "Convert property to data function": "Converti proprietà in una funzione dati",
+  "Convert property into a elevation function": "Converti proprietà in una funzione di elevazione",
   "Layer <1>{formatLayerId(layerId)}</1>: {parsed.data.message}": "Livello <1>{formatLayerId(layerId)}</1>: {parsed.data.message}",
   "switch to layer": "passa al livello",
   "Map": "Mappa",