Remove default middleware in stac_fastapi.api.app.StacApi

[vincentsarago]

Having a compression middleware is a nice thing but IMO it shouldn't be included by default.

stac-fastapi/stac_fastapi/api/stac_fastapi/api/app.py

Line 349 in 2347e6b

self.app.add_middleware(BrotliMiddleware)

My main motivation is that I often build my own custom application (and then choose what middleware to add) (e.g https://github.com/developmentseed/eoAPI/blob/master/src/eoapi/stac/eoapi/stac/app.py#L34-L44)

[geospatial-jeff]

closed in #267, thanks @vincentsarago !