Core/SpellScripts: rename GetTarget*() functions to GetExplTarget*(), so the names reflect better what those functions do. Also update some comments.

src/server/scripts/Spells/spell_generic.cpp

@@ -1282,7 +1282,7 @@ class spell_gen_launch : public SpellScriptLoader
 
             void Launch()
             {
-                WorldLocation const* const position = GetTargetDest();
+                WorldLocation const* const position = GetExplTargetDest();
 
                 if (Player* player = GetHitPlayer())
                 {