refactor: Library worker renaming

[gavin-aguiar]

Description

This PR implements a major restructuring of the Azure Functions Python Worker project to improve organization and maintainability of the codebase.

Before:
azure_functions_worker_v1/ # V1 runtime library
azure_functions_worker_v2/ # V2 runtime library
workers/

After:
runtimes/
├── v1/ # V1 runtime library
│ └── azure_functions_runtime_v1/
└── v2/ # V2 runtime library
└── azure_functions_runtime/
workers/ # (unchanged)

Fixes #

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Pull Request Checklist

Host-Worker Contract

• Does this PR impact the host-worker contract (e.g., gRPC messages, shared interfaces)?
  • If yes, have the changes been applied to:
    • azure_functions_worker (Python <= 3.12)
    • proxy_worker (Python >= 3.13)
  • If no, please explain why:

Worker Execution Logic

• Does this PR affect worker execution logic (e.g., function invocation, bindings, lifecycle)?
  If yes, please answer the following:

Python Version Coverage

• Does this change apply to both Python <=3.12 and 3.13+?
• If yes, have the changes been made to:
  • azure_functions_worker (Python <= 3.12)
  • azure_functions_worker_v1 / azure_functions_worker_v2 (Python >= 3.13)
• If no, please explain why:

Programming Model Compatibility (for Python 3.13+)

• Does this change apply to both:
  • V1 programming model (azure_functions_worker_v1)?
  • V2 programming model (azure_functions_worker_v2)?
• Explanation (if limited to one model):