reverts last 2 APC commits, restores APC charging

https://github.com/Baystation12/Baystation12/commit/4b070a2de6fe0ad555b1f8166149a49aa685304c
broke all sorts of APC things e.g. charging, mode switching, load mechanisms, etc.
e.g. they are putting a draw of max avail of the powernet while not properly translating between cell and net charge.
that means if the avail power in the net is 2MW, the APCs put a load of 2MW on the net, but don't charge with 2MW.
in return if there is zero avail power, the APCs don't require any power to stay fully charged.
also it broke chargemode switching, APCs would never stop charging.

https://github.com/Baystation12/Baystation12/commit/1cfc3b8d5ffa3f7e7f6561dbe4f55b2d923bf782 improperly tried to iron over the issues.