RESP3 response-callbacks cleanup (#2841)

* cluenup

* sentinel callbacks

* move callbacks

* fix async cluster tests

* _parsers and import fix in tests

* linters

* make modules callbacks private

* fix async search

* fix

---------

Co-authored-by: Chayim I. Kirshen <c@kirshen.com>

Author: dvora-h

redis/parsers/__init__.py renamed to redis/_parsers/__init__.py

@@ -24,6 +24,12 @@
     cast,
 )
 
+from redis._parsers.helpers import (
+    _RedisCallbacks,
+    _RedisCallbacksRESP2,
+    _RedisCallbacksRESP3,
+    bool_ok,
+)
 from redis.asyncio.connection import (
     Connection,
     ConnectionPool,
@@ -37,7 +43,6 @@
     NEVER_DECODE,
     AbstractRedis,
     CaseInsensitiveDict,
-    bool_ok,
 )
 from redis.commands import (
     AsyncCoreCommands,
@@ -257,12 +262,12 @@ def __init__(
         self.single_connection_client = single_connection_client
         self.connection: Optional[Connection] = None
 
-        self.response_callbacks = CaseInsensitiveDict(self.__class__.RESPONSE_CALLBACKS)
+        self.response_callbacks = CaseInsensitiveDict(_RedisCallbacks)
 
         if self.connection_pool.connection_kwargs.get("protocol") in ["3", 3]:
-            self.response_callbacks.update(self.__class__.RESP3_RESPONSE_CALLBACKS)
+            self.response_callbacks.update(_RedisCallbacksRESP3)
         else:
-            self.response_callbacks.update(self.__class__.RESP2_RESPONSE_CALLBACKS)
+            self.response_callbacks.update(_RedisCallbacksRESP2)
 
         # If using a single connection client, we need to lock creation-of and use-of
         # the client in order to avoid race conditions such as using asyncio.gather