Core/Instances: Add functionality for modifying instance entrance locations

Instances have since MoP (Possibly even Cataclysm) been able to set new locations for players when they zone into the instance.
A theoretic example of this could be after a certain boss has been defeated, a new entrance location is set to bring players entering the instance closer to the relevant content.
A real example would be Siege of Orgrimmar changing entrance locations many times as the raid progresses.

Added SetEntranceLocation for setting entrance locations that will be saved to DB the next time the instance is saved, and SetTemporaryEntranceLocation for when you don't want the value to be saved to the database.

Closes #17167

src/server/database/Database/Implementation/CharacterDatabase.cpp

@@ -83,7 +83,7 @@ void CharacterDatabaseConnection::DoPrepareStatements()
                      "FROM characters WHERE guid = ?", CONNECTION_ASYNC);
 
     PrepareStatement(CHAR_SEL_GROUP_MEMBER, "SELECT guid FROM group_member WHERE memberGuid = ?", CONNECTION_BOTH);
-    PrepareStatement(CHAR_SEL_CHARACTER_INSTANCE, "SELECT id, permanent, map, difficulty, extendState, resettime FROM character_instance LEFT JOIN instance ON instance = id WHERE guid = ?", CONNECTION_ASYNC);
+    PrepareStatement(CHAR_SEL_CHARACTER_INSTANCE, "SELECT id, permanent, map, difficulty, extendState, resettime, entranceId FROM character_instance LEFT JOIN instance ON instance = id WHERE guid = ?", CONNECTION_ASYNC);
     PrepareStatement(CHAR_SEL_CHARACTER_AURAS, "SELECT casterGuid, itemGuid, spell, effectMask, recalculateMask, stackCount, maxDuration, remainTime, remainCharges, castItemLevel FROM character_aura WHERE guid = ?", CONNECTION_ASYNC);
     PrepareStatement(CHAR_SEL_CHARACTER_AURA_EFFECTS, "SELECT casterGuid, itemGuid, spell, effectMask, effectIndex, amount, baseAmount FROM character_aura_effect WHERE guid = ?", CONNECTION_ASYNC);
     PrepareStatement(CHAR_SEL_CHARACTER_SPELL, "SELECT spell, active, disabled FROM character_spell WHERE guid = ?", CONNECTION_ASYNC);
@@ -290,8 +290,8 @@ void CharacterDatabaseConnection::DoPrepareStatements()
     PrepareStatement(CHAR_DEL_TUTORIALS, "DELETE FROM account_tutorial WHERE accountId = ?", CONNECTION_ASYNC);
 
     // Instance saves
-    PrepareStatement(CHAR_INS_INSTANCE_SAVE, "INSERT INTO instance (id, map, resettime, difficulty, completedEncounters, data) VALUES (?, ?, ?, ?, ?, ?)", CONNECTION_ASYNC);
-    PrepareStatement(CHAR_UPD_INSTANCE_DATA, "UPDATE instance SET completedEncounters=?, data=? WHERE id=?", CONNECTION_ASYNC);
+    PrepareStatement(CHAR_INS_INSTANCE_SAVE, "INSERT INTO instance (id, map, resettime, difficulty, completedEncounters, data, entranceId) VALUES (?, ?, ?, ?, ?, ?, ?)", CONNECTION_ASYNC);
+    PrepareStatement(CHAR_UPD_INSTANCE_DATA, "UPDATE instance SET completedEncounters=?, data=?, entranceId=? WHERE id=?", CONNECTION_ASYNC);
 
     // Game event saves
     PrepareStatement(CHAR_DEL_GAME_EVENT_SAVE, "DELETE FROM game_event_save WHERE eventEntry = ?", CONNECTION_ASYNC);
@@ -467,7 +467,7 @@ void CharacterDatabaseConnection::DoPrepareStatements()
     PrepareStatement(CHAR_SEL_POOL_QUEST_SAVE, "SELECT quest_id FROM pool_quest_save WHERE pool_id = ?", CONNECTION_SYNCH);
     PrepareStatement(CHAR_SEL_CHAR_CUSTOMIZE_INFO, "SELECT name, race, class, gender, at_login FROM characters WHERE guid = ?", CONNECTION_ASYNC);
     PrepareStatement(CHAR_SEL_CHAR_RACE_OR_FACTION_CHANGE_INFOS, "SELECT at_login, knownTitles, skin, face, hairStyle, hairColor, facialStyle FROM characters WHERE guid = ?", CONNECTION_ASYNC);
-    PrepareStatement(CHAR_SEL_INSTANCE, "SELECT data, completedEncounters FROM instance WHERE map = ? AND id = ?", CONNECTION_SYNCH);
+    PrepareStatement(CHAR_SEL_INSTANCE, "SELECT data, completedEncounters, entranceId FROM instance WHERE map = ? AND id = ?", CONNECTION_SYNCH);
     PrepareStatement(CHAR_SEL_PERM_BIND_BY_INSTANCE, "SELECT guid FROM character_instance WHERE instance = ? and permanent = 1", CONNECTION_SYNCH);
     PrepareStatement(CHAR_SEL_CHAR_COD_ITEM_MAIL, "SELECT id, messageType, mailTemplateId, sender, subject, body, money, has_items FROM mail WHERE receiver = ? AND has_items <> 0 AND cod <> 0", CONNECTION_SYNCH);
     PrepareStatement(CHAR_SEL_CHAR_SOCIAL, "SELECT DISTINCT guid FROM character_social WHERE friend = ?", CONNECTION_SYNCH);