player.Handler improvements

[FDUTCH]

This will simplify many things

[Sandertv]

Would be very helpful if you could provide actual rationale for PRs. In what ways would you use this?

[FDUTCH]

Would be very helpful if you could provide actual rationale for PRs. In what ways would you use this? I need to check every tick whether the player is in the certain blocks, I need to update the bossbar to the player in order to show how many time remained until the end of the battle, and there are many more use cases