chore: Migrate from poetry to uv for the package and all examples

[BulkBeing]

• This PR doesn't change pynumaflow_lite. I will make the changes in a separate PR.
• Made the example Dockerfiles simpler (removed dumbinit, using uv images itself as final image)
• I think its better to store uv.lock file as well. Fastapi and pydantic does it. Reason: Unignore Cargo.lock file tokio-rs/axum#3104

Almost all part of the CI including pypi publish (only upto package build, and image builds. package/image publishing step was skipped) were tested https://github.com/BulkBeing/numaflow-python/pull/1/checks?sha=9a0656ad44fc0027e8f7a167440484baee754ab6

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 94.31%. Comparing base (5b458ad) to head (445f7ba).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #335      +/-   ##
==========================================
- Coverage   94.40%   94.31%   -0.10%     
==========================================
  Files          67       67              
  Lines        3182     3182              
  Branches      179      179              
==========================================
- Hits         3004     3001       -3     
- Misses        143      146       +3     
  Partials       35       35              

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[vigith]

do we need these uv.lock?

[BulkBeing]

do we need these uv.lock?

I think its good for reproducible builds. Fastapi and pyadantic is storing it in Git.