MVP Tomb save timer on Server Restart 2.0.0

*2025-03-17 - Updated works for latest rathena

1) Upon killing MVPs, it will save the date and time of death, killer , monster and map where it was killed in the database.

2) During server restart, reload or sudden crash, before spawning mobs, it will check and differentiate the date and time saved in the database with the current server time and check if the MVP should be alive or dead.
- If ALIVE, should spawn the MVP
- If DEAD, will not spawn the MVP, spawn the tomb (if tomb is enabled in the server config) and create a timer to spawn the MVP from the time it was killed