fix rebirth issues: deequip all gear types, reset levelDrops, wipe buffs

Changes rebirth to:

- deequip all types of gear even those not invented yet - fixes https://github.com/HabitRPG/habitrpg/issues/3377

- wipe all buffs - fixes https://github.com/HabitRPG/habitrpg/issues/3077

- allow player to receive level drops (e.g., vice1 at level 30) - fixes https://github.com/HabitRPG/habitrpg/issues/2873