Refactor simulation cluster management and improve gRPC handling

[dJaniga]

Abstracted Docker-based simulation cluster management into a new SimulationClusterManager class. Replaced ad-hoc gRPC stub creation with a reusable GrpcStubManager for better resource handling. Miscellaneous improvements include added dynamic worker count, logging enhancements, and inclusion of the psutil library for CPU-based scaling logic.

• Type of Change:
  • New feature
  • Bug fix
  • Code refactoring
  • Documentation update
  • Other (please describe):

Ensure that all the following tasks are completed before submitting your PR:

• Code is formatted and has been linted using 'makefile' run-check option
• New and existing tests pass locally.
• All relevant documentation has been updated (e.g., docstrings, README, etc.).
• Dependencies have been updated in pyproject.toml, and uv.lock has been regenerated accordingly.
• This PR has been reviewed by at least one other developer.