[feat] support prefix cache clearing when /clear_load_weight is called (#4008)

* [feat] support clearing prefix cache (cherry-picked from release/2.1)

* [fix] fix ipc suffix, use port instead

* [fix] fix prefix caching not enabled

* [fix] fix key/value_cache_scales indent

* [fix] fix ep group all-reduce

* [fix] fix clear/update lock not working when workers > 1

* [chore] add preemption triggered info log

* [fix] fix code style

* [fix] fix max_num_seqs config

* [fix] do not force enable_prefix_caching=False in dynamic loading

* [fix] fix ci

* Revert "[fix] fix ci"

This reverts commit 0bc6d55cc8.

* [fix] initialize available_gpu_block_num with max_gpu_block_num

* [fix] fix config splitwise_role

* [fix] fix clearing caches synchronization and add more logs

* [chore] print cache_ready_signal in log

* [fix] fix scheduler_config.splitwise_role

* [fix] fix cache_messager cache_ready_signal create=True

* [fix] stop cache messager from launching in mixed deployment

fastdeploy/inter_communicator/__init__.py

@@ -17,15 +17,25 @@
 from .engine_cache_queue import EngineCacheQueue
 from .engine_worker_queue import EngineWorkerQueue
 from .ipc_signal import IPCSignal, shared_memory_exists
+from .ipc_signal_const import (
+    ExistTaskStatus,
+    KVCacheStatus,
+    ModelWeightsStatus,
+    PrefixTreeStatus,
+)
 from .zmq_client import ZmqIpcClient
 from .zmq_server import ZmqIpcServer, ZmqTcpServer
 
 __all__ = [
     "ZmqIpcClient",
+    "ZmqIpcServer",
+    "ZmqTcpServer",
     "IPCSignal",
     "EngineWorkerQueue",
     "EngineCacheQueue",
-    "ZmqTcpServer",
-    "ZmqIpcServer",
     "shared_memory_exists",
+    "ExistTaskStatus",
+    "PrefixTreeStatus",
+    "ModelWeightsStatus",
+    "KVCacheStatus",
 ]