Construct the composition series of Garsia-Procesi modules

[tscrim]

We provide an implementation of Garsia-Procesi modules, which are an important class of representations of the symmetric group that comes from the cohomology of the Springer fiber. This provides an implementation as a representation on a quotient ring. This also does the following as part of getting the code to work (and a few related changes):

• Implement the meataxe algorithm over finite fields to compute the composition series.
• Move the (Brauer) character and other methods from symmetric group representation to the general representation class.
• Made the abstract representation class work more generically and streamlined the implementation.
• Expose the Representation class as part of the semigroup (algebras) API.

:memo: Checklist

• [x] The title is concise and informative.
• [x] The description explains in detail what this PR is about.
• [x] I have linked a relevant issue or discussion.
• [x] I have created tests covering the changes.
• [x] I have updated the documentation and checked the documentation preview.

:hourglass: Dependencies

[github-actions[bot]]

Documentation preview for this PR (built with commit d7fd435969c46418f2801f526b0758c786efeb77; changes) is ready! :tada: This preview will update shortly after each push to this PR.