Fix multiblock energy storage charging when reaching int.max

[GotoFinal]

Description

Small fix to make multiblock capacitor accept more than int.max energy.

Also small optimisation to code extracting/receiving energy - but I believe this code overall could use more love... But I don't personally use enderio much for it and it requires bigger work so not motivated myself...
Currently every operation on multiblock copies the data from graph, shuffles it, and iterates over all elements (well now not always all), this will make these multiblock structures to cause quite high load, especially when they are big and empty/full, as each operation will repeat every tick doing nothing.

Closes #302

Checklist:

• My code follows the style guidelines of this project (.editorconfig, most IDEs will use this for you).
• I have performed a self-review of my own code.
• I have commented my code in areas it may be challenging to understand.
• I have made corresponding changes to the documentation.
• My changes are ready for review from a contributor.

[GotoFinal]

I'm a bit confused by the milestones now, the issue this PR fixes is in 6.0, yet the PR is in 6.1? @Rover656

[Rover656]

Milestones are currently being shifted around, this one should probably continue to target 6.0, I'll fix this :) Cheers

[Rover656]

Just so you know; I'm not forgetting about this one either, I'd just like to let agnor decide if these changes make sense, as I didn't have any part in how this system works :)

[agnor99]

works, I wanted to do some performance improvements for cap banks, but this is a good fix for the time being, thanks a lot