feat(Core/Commands): GM command to display strings (#6268)

- Implements a new GM command to display strings from the acore_string table
- Syntax: .string #id [#locale]
- Closes https://github.com/azerothcore/azerothcore-wotlk/issues/1052

src/server/game/Miscellaneous/Language.h

@@ -1195,6 +1195,9 @@ enum AcoreStrings
 
     LANG_GM_SILENCE                      = 6616,              // "Silence is ON for %s" - Spell 1852
 
+    // Used for .string command
+    LANG_NO_ACORE_STRING_FOUND           = 6617,
+
     LANG_WORLD_CLOSED                    = 7523,
     LANG_WORLD_OPENED                    = 7524,