[Zones] Convert IDLE_WHEN_EMPTY to a Zone Column (#3891)

* [Rules] Convert IDLE_WHEN_EMPTY to a rule

# Notes
- Converts `IDLE_WHEN_EMPTY` to `Zone:ZonesIdleWhenEmpty` so that we can change this on the fly or on a zone-by-zone basis instead of having to recompile to do this.
- Especially helpful for those using release binaries that do not compile their own source.

* Convert to zone column.

* Update ruletypes.h

* Update ruletypes.h

* Update entity.cpp

* Update entity.cpp

* Rename.

* Update database_update_manifest.cpp

* Update base_zone_repository.h

* Update zone.cpp

* seconds_before_idle

* Update database_update_manifest.cpp

* Getter/Setters/Private

* Update base_zone_repository.h

* IsIdle()/SetIsIdle()

* Update entity.cpp

common/database/database_update_manifest.cpp

@@ -5186,7 +5186,19 @@ ALTER TABLE `instance_list`
 	ADD COLUMN `notes` varchar(50) NOT NULL DEFAULT '' AFTER `never_expires`;
 )",
 	},
-
+	ManifestEntry{
+		.version = 9252,
+		.description = "2024_01_07_zone_idle_when_empty.sql",
+		.check = "SHOW COLUMNS FROM `zone` LIKE 'idle_when_empty'",
+		.condition = "empty",
+		.match = "",
+		.sql = R"(
+ALTER TABLE `zone`
+ADD COLUMN `idle_when_empty` tinyint(1) UNSIGNED NOT NULL DEFAULT 1 AFTER `min_lava_damage`
+ADD COLUMN `seconds_before_idle` int(11) UNSIGNED NOT NULL DEFAULT 60 AFTER `idle_when_empty`
+)",
+		.content_schema_update = true
+	}
 // -- template; copy/paste this when you need to create a new entry
 //	ManifestEntry{
 //		.version = 9228,