chore(weave): Further split out Query/Trace

[andrewtruong]

Summary

Do not merge until after weave 0.50.15 release!

Corresponding change in core: https://github.com/wandb/core/pull/23467

1. This PR moves a lot of code and reorganizes the repo in prep to eject the query and trace server code.
   1. Legacy code is moved to weave/legacy/
   2. Trace code is kept in the top-level weave/
   3. Splits out the legacy W&B api dependency into its own submodule wandb_api
   4. Dependencies of trace on query are minimized -- what remains are mostly in tests, or relate to storage, urls, context_state, artifact_fs, and some stuff for fastapi
   5. Tests and CI are broken out for trace and query.
      1. Tests are moved to to either weave/tests/ (for trace), or weave/legacy/tests/ (for legacy)
      2. mypy.ini is split into trace and legacy
      3. pre-commit hooks are updated for trace and legacy
   6. Scripts, docs, misc files are consolidated where it makes sense and updated for readability
   7. Top-level requirements now reflect just the trace code -- legacy requirements moved to weave/legacy/requirements.* -- Deferred to simplify this PR
   8. mypy.ini broken out for trace and legacy respectively

Review suggestions

1. This change seems large, but is mostly file moving and updating paths. The best way to review is probably to view the directory and see how files have shifted
2. This is similar to the previous legacy refactor and will require a force merge to resolve the dual-dependency in core.

Missing pieces (too hard atm):

1. conftest.py
2. weave_server.py
3. weave_server.sh
4. weave-js/
5. frontend/
6. trace_server/
7. integration_test/
8. Fully eject all deps from trace (and some from query)

[circle-job-mirror]

Preview this PR with FeatureBee: https://beta.wandb.ai/?betaVersion=880fe421e0f259fbce6bc0cbc63c03534444dc35