[HLAPI] Some schema validity fixes and changes

[cconard96]

Checklist before requesting a review

• I have read the CONTRIBUTING document.
• I have performed a self-review of my code.
• I have added tests that prove my fix is effective or that my feature works.

Description

• Added some missing constraints.
• Added some missing properties for v2.1.
• Added test to identify missing properties for schemas for CommonTreeDropdown itemtypes.
• Added test to ensure all schemas, even if they don't have a REST endpoint, can be correctly used in the search (catch invalid properties).
• Added test to catch duplicate schemas.

Nothing here should be a BC break.
See CHANGELOG for more information.

With the new GraphQL test, I identified a property name mismatch between the partial and full schemas for Users. In the full schema, the name field is exposed as "username" while the partial still shows it as "name". This is annoying but doesn't block the use. The GraphQL schemas all show the correct property name "username" for dropdowns since it expands the partial schemas automatically. A note and assertion was added in the test to enforce that it is fixed for v3 of the API.

Also found there are duplicate SoftwareLicense and License schemas. They will be fixed in v3 but for now at least there is a check to ensure they have the same properties. Again, not a blocker but just an annoyance or point of user confusion.