Update renders for titiler-pgstac v1

[anayeaye]

What

The renders preview url was not updated for the breaking /stac/preview --> /collections/{collection_id}/items/{item_id}/preview .

For example:

https://test.openveda.cloud/api/raster/stac/preview.png?collection=nightlights-hd-1band&item=BeforeMaria_Stage0_2017-07-21_2017-09-19_1band&bidx=1&assets=cog_default&rescale=0%2C255&colormap_name=inferno

should be https://test.openveda.cloud/api/raster/collections/nightlights-hd-1band/items/BeforeMaria_Stage0_2017-07-21_2017-09-19_1band/preview?assets=cog_default&colormap_name=inferno

AC

• rendered previews work for items in collections with renders metadata