Titiler-pgstac

* add `tilejson` URL links for `layers` defined in mosaic's metadata in `/mosaic/register` and `/mosaic/{mosaic_id}/info` response
* support multiple `layers` in `/mosaic/{mosaic_id}/WMTSCapabilities.xml` endpoint created from mosaic's metadata

**breaking change**

* In `/mosaic/WMTSCapabilities.xml` we removed the query-parameters related to the `tile` endpoint (which are forwarded) so `?assets=` is no more required.
The endpoint will still raise an error if there are no `layers` in the mosaic metadata and no required tile's parameters are passed.

python
before
response = httpx.get("/mosaic/{mosaic_id}/WMTSCapabilities.xml")
assert response.status_code == 400

response = httpx.get("/mosaic/{mosaic_id}/WMTSCapabilities.xml?assets=cog")
assert response.status_code == 200

now
If the mosaic has `defaults` layers set in the metadata
we will construct a WMTS document with multiple layers, so no need for the user to pass any `assets=`
response = httpx.get("/mosaic/{mosaic_id}/WMTSCapabilities.xml")
assert response.status_code == 200
with rasterio.open(io.BytesIO(response.content)) as src:
assert src.profile["driver"] == "WMTS"
assert len(src.subdatasets) == 2

If the user pass any valid `tile` parameters, an additional layer will be added to the one from the metadata
response = httpx.get("/mosaic/{mosaic_id}/WMTSCapabilities.xml?assets=cog")
assert response.status_code == 200
with rasterio.open(io.BytesIO(response.content)) as src:
assert src.profile["driver"] == "WMTS"
assert len(src.subdatasets) == 3

* add `python-dotenv` requirement

* update `titiler` requirement to `>=0.12.0,<0.13`
* use `Annotated` Type for Query/Path parameters
* re-order endpoints in `MosaicTilerFactory` to avoid conflicts between `tiles` and `assets` endpoints
* remove `stac-pydantic` dependency
* add optional `root_path` setting to specify a url path prefix to use when running the app behind a reverse proxy
* add landing page `/`
* use `lifespan` option instead of deprecated `app.on_event` method to initiate/close DB connection

**breaking changes**

* remove deprecated `/{searchid}/{z}/{x}/{y}/assets` endpoints
* use /api and /api.html for documentation (instead of /openapi.json and /docs)
* replace Enum's with `Literal` types
* replace variable `TileMatrixSetId` by `tileMatrixSetId`
* add `pixel_selection_dependency` attribute to the `MosaicTilerFactory`

* update `titiler` requirement to `>=0.11.7`
* fix `/map` endpoint template name
* rename `add_map_viewer` to `add_viewer` option in `MosaicTilerFactory` for consistency with `titiler's` options

* remove deprecated `/tiles/{searchid}/...` endpoints (replaced with `/{searchid}/tiles/...`)
* depreciate `/{searchid}/{z}/{x}/{y}/assets` endpoints and add `/{searchid}/tiles/{z}/{x}/{y}/assets`
* update minimum titiler requirement to `>=0.11.6`
* remove timing headers
* add `strict_zoom` option (controled with `MOSAIC_STRICT_ZOOM` environment variable) to raise (or not) error when fetching tile outside mosaic min/max zoom range

* update python packaging/build system to `pdm-pep517`
* use `Ruff` for lint
* add retry mechanism on Database connection issues for `PGSTACBackend.get_assets()` and `get_stac_item` methods (back ported from 0.2.4)