OAFeat Filter Extension

[drnextgis]

I encountered this issue while working with the stac-browser and reported it here: radiantearth/stac-browser#483.

It seems that stac-fastapi currently doesn't support the Filter Extension, as referenced here: https://github.com/radiantearth/stac-api-spec/tree/738f4837ac6bea041dc226219e6d13b2c577fb19/ogcapi-features#filter-extension. filter is not included in the list of supported GET parameters:

[vincentsarago]

@drnextgis the filter extension exists, it's up to the application developer to allow it or no in their endpoints!

on stac-fastapi-pgstac, the code is ready for it https://github.com/stac-utils/stac-fastapi-pgstac/blob/9a3797a149f17491735a6134109363f681d934c5/stac_fastapi/pgstac/core.py#L351-L360. but the application doesn't use a GET model with the filter extension enabled https://github.com/stac-utils/stac-fastapi-pgstac/blob/main/stac_fastapi/pgstac/app.py#L61C1-L70