Migrate contribs client to main client

[esoteric-ephemera]

See MPContribs #1982 for more details about client reorganization.

Pulls mpcontribs-client into mp_api as an optional add-on. Changes include:

• Reorganize client into modules for easier editing
• Replace some quasi-deprecated packages in favor of those already in the stack (e.g., ujson in favor of orjson)
• Align the syntaxes of the main API client and the MPC client (i.e., consistent naming of class kwargs)
• dynamically constructed pydantic models for returned data types in contribs

[codecov-commenter]

Codecov Report

❌ Patch coverage is 44.10894% with 944 lines in your changes missing coverage. Please review.
✅ Project coverage is 69.92%. Comparing base (a08a927) to head (603b80f).

Files with missing lines	Patch %	Lines
mp_api/client/contribs/client.py	35.88%	713 Missing ⚠️
mp_api/client/contribs/_types.py	33.66%	134 Missing ⚠️
mp_api/client/contribs/schemas.py	66.90%	46 Missing ⚠️
mp_api/client/contribs/utils.py	48.27%	30 Missing ⚠️
mp_api/client/core/schemas.py	84.28%	11 Missing ⚠️
mp_api/client/contribs/logger.py	85.71%	6 Missing ⚠️
mp_api/client/contribs/settings.py	91.48%	4 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##             main    #1075       +/-   ##
===========================================
- Coverage   86.82%   69.92%   -16.91%     
===========================================
  Files          47       56        +9     
  Lines        2680     4306     +1626     
===========================================
+ Hits         2327     3011      +684     
- Misses        353     1295      +942     

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