support the profile parameter for detailed info on the requested encoding

**Is your feature request related to a problem? Please describe.**

for some specialised formats such as jsonfg, ogc suggests to reuse the application/geo+json encoding, but extend it with a profile parameter to indicate the json flavour.

**Describe the solution you'd like**

pygeoapi would parse the profile to understand which json to return. This functionality will also be relevant for other json flavour, such as stac, ogcapi-records, cov-json, etc

the profile can also de introduced as query parameter, to override the accept header, ?f=geojson&profile=jsonfg, however a shortcut f=jsonfg also makes sense.

**Additional context**

https://docs.ogc.org/is/21-045r1/21-045r1.html#_using_a_json_fg_client

This came up as part of #2376