【Hackathon 10th Spring No.36】[Tests] add unit tests for worker/worker_process.py

Add 54 unit tests covering:
- get_worker(): CUDA/DCU platform dispatch, logprob import error
- update_fd_config_for_mm(): Ernie/non-Ernie config, disabled mode
- PaddleDisWorkerProc: init, control, health status, load model,
  device init, graph optimize, KV cache, EPLB, barrier wait,
  control methods, task queue, broadcast weights
- parse_args(): defaults, custom values, JSON configs, MOE, logprob,
  overlap scheduling, boolean flags
- initialize_fd_config(): end-to-end config assembly
- update_weights_from_tensor(): weight update flow

All tests run on CPU with mocked GPU/distributed dependencies.

Author: cloudforge1