[GH-13106] Migrate channelMemberCountsCache cache from store/sqlstore/channel_store.go to the new store/localcachelayer (#13128)

* Migrate channelMemberCountsCache cache from store/sqlstore/channel_store.go to the new store/localcachelayer

* Move cache functions to layer functions over the caches

* Directly remove and purge caches in handleClusterInvalidate to avoid loops and prepare details for layer with multiple caches

model/cluster_message.go

@@ -24,6 +24,7 @@ const (
 	CLUSTER_EVENT_CLEAR_SESSION_CACHE_FOR_USER                      = "clear_session_user"
 	CLUSTER_EVENT_INVALIDATE_CACHE_FOR_ROLES                        = "inv_roles"
 	CLUSTER_EVENT_INVALIDATE_CACHE_FOR_SCHEMES                      = "inv_schemes"
+	CLUSTER_EVENT_INVALIDATE_CACHE_FOR_CHANNEL_MEMBER_COUNTS        = "inv_channel_member_counts"
 	CLUSTER_EVENT_CLEAR_SESSION_CACHE_FOR_ALL_USERS                 = "inv_all_user_sessions"
 	CLUSTER_EVENT_INSTALL_PLUGIN                                    = "install_plugin"
 	CLUSTER_EVENT_REMOVE_PLUGIN                                     = "remove_plugin"