[Feature] Add Experience Gain Toggle. (#2676)

* [Feature] Add Experience Gain Toggle.

# Perl
- Add `$client->IsEXPEnabled()`.
- Add `$client->SetEXPEnabled(is_exp_enabled)`.

# Lua
- Add `client:IsEXPEnabled()`.
- Add `client:SetEXPEnabled(is_exp_enabled)`.

# Commands
- Add `#exptoggle [Toggle] - Toggle your or your target's experience gain.`.

# Notes
- Allows operators to turn on/off a player's experience gain individually without changing their rule values.
- The command allows operators to give players access to the command to disable their own experience gain.

utils/sql/db_update_manifest.txt

@@ -467,6 +467,7 @@
 9211|2022_10_14_fix_neriak_pok_stone.sql|select * from doors where id = 2057 and `name` = 'POKNRKPORT500' and client_version_mask = 4294967232|empty|
 9212|2022_10_14_fix_misty_pok_stone.sql|select * from doors where id = 2040 and `name` = 'POKRVPORT500' and dest_zone = 'misty'|empty|
 9213|2022_12_24_npc_keeps_sold_items.sql|SHOW COLUMNS FROM `npc_types` LIKE 'keeps_sold_items'|empty|
+9214|2022_12_24_character_exp_toggle.sql|SHOW COLUMNS FROM `character_data` LIKE 'exp_enabled'|empty|
 
 # Upgrade conditions:
 # 	This won't be needed after this system is implemented, but it is used database that are not

utils/sql/git/required/2022_12_15_character_exp_toggle.sql

@@ -0,0 +1,2 @@
+ALTER TABLE `character_data`
+ADD COLUMN `exp_enabled` tinyint(1) UNSIGNED NOT NULL DEFAULT 1 AFTER `exp`;