Clarify consistency regarding presence of elements at /collections and /collections/{collectionId}

[jerstlouis]

Clarify whether elements in /collections vs. in /collections/{collectionId} need to be consistent, but that an element being omitted from /collections but present /collections/{collectionId} still count as consistent.
This is different than Features where the interpretation is that if one is present at one location it needs to be in both.

[cmheazel]

Removed part C from Requirement 8.
API Common Part 2 now does not say anything about consistency between /collections and /collections/{collectionId} responses. All that is required is that they both comply with the requirements in the http://www.opengis.net/spec/ogcapi-common-2/1.0/rm/collection Requirements Module. This allows a SWG to use simplified representations of the /collections/{collectionId} response in the /collections response where appropriate.

[jerstlouis]

Actually what Features states in Requirement 19 B is:

The content of that response SHALL be consistent with the content for this feature collection in the /collections response.
That is, the values for id, title, description, extent and itemType SHALL be identical and links SHALL include all links included for this feature collection in the /collections response.

So the interpretation of Features seems to be exactly what I was suggesting above.

There's also no mention of access mechanism links in particular needing to be included at the /collections level in any of Maps, Tiles, DGGS or Coverages, which does mean that if this information is not included at /collections, clients will have to make separate requests to individual collections to understand which access mechanisms are supported for each.