Adding support for RF6902 for path requests.

[rhysrevans3]

Related Issue(s):

• Is JSON Merge PATCH RFC7396 compatible with STAC? #13

Proposed Changes:

1. Adding support for RFC 6902 to PATCH.
2. Updating RFC 7386 support to RFC 7396 in PATCH.

PR Checklist:

• This PR has no breaking changes.
• I have added my changes to the CHANGELOG or a CHANGELOG entry is not required.

[rhysrevans3]

I've added the original application/json content type back as to not cause any breaking changes. This is not technically correct for RFC 7396.

[vincentsarago]

@m-mohr would you be wiling to review this?

[m-mohr]

This primarily needs to be in accordance with OGC APIs corresponding part. If we have an issue in STAC, OGC may also have one. Can someone check with them? I'd probably be fine with this if OGC also adopts this. I'd try to avoid diverging from OGC.

I'm traveling/on vacation the next 4 weeks so would only be able to review in November, I think.