[Refactor]Refactor of vllm_ascend/distributed module (#5719)

### What this PR does / why we need it?
Based on the RFC:https://github.com/vllm-project/vllm-ascend/issues/5604

This PR is a refactoring of vllm_ascend/distributed, moving all
kv_transfer realtaed codes into a dedicated folder, which has already
been done in vLLM

### Does this PR introduce _any_ user-facing change?
NA

### How was this patch tested?


- vLLM version: v0.13.0
- vLLM main:
2f4e6548ef

---------

Signed-off-by: lty <linhebiwen@gmail.com>

tests/ut/kv_connector/utils.py

@@ -79,8 +79,7 @@ def create_vllm_config(
     )
     kv_transfer_config = KVTransferConfig(
         kv_connector="MooncakeConnectorV1",
-        kv_role="kv_both",
-        kv_connector_module_path="vllm_ascend.distributed.mooncake_connector")
+        kv_role="kv_both")
     return VllmConfig(scheduler_config=scheduler_config,
                       model_config=model_config,
                       cache_config=cache_config,