[Feature] Conformance Tests

All conformance link items should be evaluated with specific test-case according to Test Method row of each table corresponding to the relevant conformance class in https://docs.ogc.org/DRAFTS/18-062.html
relates to #53

~~For easier identification of conformance specific tests, they should be placed in a separate test_conformance.py file.~~

All items from :

... that are implemented by Weaver should be listed ~~in the documentation (new conformance.RST file)~~
directly in the /conformance response.

weaver/weaver/wps_restapi/api.py

Lines 177 to 181 in 858ea46

    
           def api_conformance(request):  # noqa: F811 
        
               # type: (Request) -> HTTPException 
        
               """Weaver specification conformance information.""" 
        
               # TODO: follow updates with https://github.com/geopython/pygeoapi/issues/198 
        
               conformance = {"conformsTo": [

Example:
http://www.opengis.net/spec/ogcapi-processes-1/1.0/req/core/process (/req/... path defined in file) for
https://github.com/opengeospatial/ogcapi-processes/blob/master/core/requirements/core/REQ_process-op.adoc

Can refer to ogcapi-common, ogcapi-processes-1, etc. requirements.

Function tests that provide the validation of the relevant requirements/recommendations/abstract-tests should have a URL reference in their docstring for quick retrieval of validators across the code.
Ex:

def test_conformance_rc_links():
    """
    .. seealso::
        - `/req/collections/rc-links <https://github.com/opengeospatial/ogcapi-common/blob/Working/collections/requirements/collections/REQ_rc-links.adoc>`_
    """
    # validation tests here

New features to add tests if implemented:

Some existing features to add to the table:

#236
#237

OGC Executable Test Suite:

#594

	def api_conformance(request): # noqa: F811
	# type: (Request) -> HTTPException
	"""Weaver specification conformance information."""
	# TODO: follow updates with https://github.com/geopython/pygeoapi/issues/198
	conformance = {"conformsTo": [