Swinging Improvements

[ikabod-kee]

• Make each swing decrease durability in real time (should fix a bug where tools don't break correctly)
• Only register block breaking per swing (in between swings, you should be able to look away briefly)
• Once a swing is initated, it shouldn't be able to be cancelled unless you switch hotbar slots.

I know the current implementation is just a stand-in. It should still follow the principles established in #803 and #953

[Argmaster]

I would add my cents and suggest to preserve damage state for all blocks that were damaged.
This can be used in the future for explosions or decaying leaves.
Block would automatically heal part of the damage (eg. 10% max health) every N ticks.
This auto healing can be used as a replacement for hard damage threshold, as blocks will be able to out heal inflicted damage if tool is too weak.
Damage state should not be saved between leaving and joining the world (if you need a reason, let's say that we assume that player leaves the world for long enough for blocks to heal or whatever)
Damage should be synced with server and retained between players.