DynamicEnums and Schemasheets integration

[mavaylon1]

Motivation

What was the reasoning behind this change? Please explain the changes briefly.

Currently to create a TermSet a user has to manually add the permissible values to the enumeration. This is not scalable and so we want to take advantage of the LinkML tools that should make creating schemas easier.
The goal of this PR is to add support for

• LinkML schemasheets in TermSet
• LinkML integration for Dynamic TermSet
• Updated documentation

How to test the behavior?

Show how to reproduce the new behavior (can be a bug fix or a new feature)

Run the unit tests.

Checklist

• Did you update CHANGELOG.md with your changes?
• Have you checked our Contributing document?
• Have you ensured the PR clearly describes the problem and the solution?
• Is your contribution compliant with our coding style? This can be checked running ruff from the source directory.
• Have you checked to ensure that there aren't other open Pull Requests for the same change?
• Have you included the relevant issue number using "Fix #XXX" notation where XXX is the issue number? By including "Fix #XXX" you allow GitHub to close issue #XXX when the PR is merged.

[oruebel]

Overall the PR looks good. I added a few comments below, but those should all be easy/quick to fix.

[mavaylon1]

Overall the PR looks good. I added a few comments below, but those should all be easy/quick to fix.

I really appreciate it! I made most of the changes, but also I left some notes to clarify some the methods both here and in the docstring as to why it is setup the way it is.