Release r2.1 with NSB v0.2.0-rc.1 and NSA v0.1.0-rc.1

[XunliYang]

What type of PR is this?

Add one of the following kinds:

• subproject management

What this PR does / why we need it:

Release r2.1 with network-slice-booking v0.2.0-rc.1 and network-slice-assignment v0.1.0-rc.1

• Modify API version from wip to 0.2.0-rc.1/0.1.0-rc.1
• Add r2.1 CHANGELOG
• API Readiness Checklist

Which issue(s) this PR fixes:

Fixes #

Special notes for reviewers:

Changelog input

 release-note

[tanjadegroot]

Hi all,
quite some comments on the new API

I recommend to

• change this to a DRAFT Release PR, do the changes on main in normal PRs.
• wait for the Release PRs of Commonalities and ICM to be available and do the relevant adjustments (if any)
• then re-open and resynch the Release PR only after all required changes are done

[XunliYang]

@tanjadegroot, thanks for your review. We have addressed comments and updated the code accordingly. Please take another look when you have a moment.

Most of problems are fixed in [Modify network-slice-assignment API Path and Feature Files #96](#96):

• Reformat network-slice-assignment API Path
  • /slices/{sliceId}/devices:
    post: # Assign device to slice
    get: # Get devices assigned to slice
  • /slices/{sliceId}/release:
    post: # Release device from slice (verb path, device in body)
  • /retrieve-slices:
    post: # Retrieve slices by device (verb path, device in body)
• Add the definition of notificationsBearerAuth in both API definitions
• Modify schema CreateSlice to SliceAttributes
• Modify description unbind --> release - consistent terminology helps understanding
• Modify schema SliceDevice --> SliceDevices (as the type is a list)
• Modify OperationId in API definition YAMLs (AssignDevice, releaseDevice, getDevices, retrieveSlicesByDevice)
• Modify feature filenames to consistent with operationId

Version problems are modified in this PR:

• CHANGELOG.MD: Add r2.1 in the table of contents.
• README.md: Update the link version and links for NSA API.
• API definition: Correct the version
• Checklist: link the ICM version with r3.3 (will modify in the public release), add the API description for NSA API