[Commands] Convert NPC Spawn Methods to Repositories (#3956)

* [Commands] Convert NPC Spawn Methods to Repositories

# Notes
- Convert `AddNewNPCSpawnGroupCommand()`, `AddNPCTypes()`, `AddSpawnFromSpawnGroup()`, `CreateNewNPCCommand()`, `DeleteSpawnLeaveInNPCTypeTable()`, `DeleteSpawnRemoveFromNPCTypeTable()`, `NPCSpawnDB()`, and `UpdateNPCTypeAppearance()`.

* Regenerate.

* Cleanup.

common/repositories/base/base_spawngroup_repository.h

@@ -16,6 +16,7 @@
 #include "../../strings.h"
 #include <ctime>
 
+
 class BaseSpawngroupRepository {
 public:
 	struct Spawngroup {

common/repositories/npc_types_repository.h

@@ -44,7 +44,32 @@ public:
      */
 
 	// Custom extended repository methods here
+	static uint32 GetOpenIDInZoneRange(Database& db, uint32 zone_id)
+	{
+		const uint32 min_id = zone_id * 1000;
+		const uint32 max_id = min_id + 999;
 
+		auto results = db.QueryDatabase(
+			fmt::format(
+				"SELECT MAX({}) FROM `{}` WHERE `{}` BETWEEN {} AND {}",
+				PrimaryKey(),
+				TableName(),
+				PrimaryKey(),
+				min_id,
+				max_id
+			)
+		);
+
+		if (!results.Success() || !results.RowCount()) {
+			return 0;
+		}
+
+		auto row = results.begin();
+
+		const uint32 npc_id = row[0] ? Strings::ToUnsignedInt(row[0]) + 1 : 0;
+
+		return npc_id < max_id ? npc_id : 0;
+	}
 };
 
 #endif //EQEMU_NPC_TYPES_REPOSITORY_H