Cherry pick some db commits (#24713)

* Core/DBLayer: Implement async transaction completion callbacks

(cherry picked from commit 0f0ca3a919)

# Conflicts:
#	src/server/bnetserver/REST/LoginRESTService.cpp
#	src/server/bnetserver/Server/Session.cpp
#	src/server/bnetserver/Server/Session.h
#	src/server/database/Database/Transaction.cpp
#	src/server/game/Handlers/CharacterHandler.cpp
#	src/server/game/Handlers/SpellHandler.cpp
#	src/server/game/Server/WorldSession.cpp
#	src/server/game/Server/WorldSocket.cpp
#	src/server/game/Server/WorldSocket.h

* Core/Misc: Fixed char enum packet sometimes not showing newly created character when client latency is too low

(cherry picked from commit fc9d2e728e)

# Conflicts:
#	src/server/game/Handlers/CharacterHandler.cpp

* Fix no-pch build

* Core/Player: Wait for correct transaction on character creation

(cherry picked from commit 01c68b2aa2)

# Conflicts:
#	src/server/game/Entities/Player/Player.cpp

* Fix warning

* Remove unused login transaction

Co-authored-by: Shauren <shauren.trinity@gmail.com>

src/server/database/Database/QueryCallback.cpp

@@ -175,7 +175,7 @@ void QueryCallback::SetNextQuery(QueryCallback&& next)
     MoveFrom(this, std::move(next));
 }
 
-QueryCallback::Status QueryCallback::InvokeIfReady()
+bool QueryCallback::InvokeIfReady()
 {
     QueryCallbackData& callback = _callbacks.front();
     auto checkStateAndReturnCompletion = [this]()
@@ -185,15 +185,15 @@ QueryCallback::Status QueryCallback::InvokeIfReady()
         if (_callbacks.empty())
         {
             ASSERT(!hasNext);
-            return Completed;
+            return true;
         }
 
         // abort chain
         if (!hasNext)
-            return Completed;
+            return true;
 
         ASSERT(_isPrepared == _callbacks.front()._isPrepared);
-        return NextStep;
+        return false;
     };
 
     if (!_isPrepared)
@@ -217,5 +217,5 @@ QueryCallback::Status QueryCallback::InvokeIfReady()
         }
     }
 
-    return NotReady;
+    return false;
 }