sage.combinat.cluster_algebra_quiver: Modularization fixes, update # needs

[mkoeppe]

• # optional with standard features are replaced by # needs
• Some import fixes needed for separate testing of sagemath-graphs from Modularization of sagelib: Distributions sagemath-{brial,combinat,eclib,flint,gap,giac,glpk,graphs,groups,homfly,lcalc,libbraiding,libecm,linbox,modules,mpmath,ntl,pari,plot,polyhedra,schemes,singular,standard-no-symbolics,symbolics} #35095

This is:

• done with the help of sage -fixdoctests from Add style guide / reference for # optional - sage.... doctest tags, extend sage -t and sage -fixdoctests for modularization tasks #35749
• Part of: Meta-ticket: Modularize sagelib into separate distributions (pip-installable packages) sagemath-... for Sage 10.x #29705
• Cherry-picked from: Modularization of sagelib: Distributions sagemath-{brial,combinat,eclib,flint,gap,giac,glpk,graphs,groups,homfly,lcalc,libbraiding,libecm,linbox,modules,mpmath,ntl,pari,plot,polyhedra,schemes,singular,standard-no-symbolics,symbolics} #35095

📝 Checklist

• The title is concise, informative, and self-explanatory.
• The description explains in detail what this PR is about.
• I have linked a relevant issue or discussion.
• I have created tests covering the changes.
• I have updated the documentation accordingly.

⌛ Dependencies

[github-actions]

Documentation preview for this PR (built with commit 711b983; changes) is ready! 🎉

[dcoudert]

LGTM.

[mkoeppe]

Thank you!