Remove overkill damage and fix some bugs in eHP

[QuickStick123]

Fixes: #4992 #5161 #5178
For reference: #4993

Description of the problem being solved:

eHP has breakpoints. This means when you have very low hits to death eHP won't change on moderate increases in health or damage reduction e.g. 20%.

This also refactors how infinite eHP is determined and when to stop. This is done by checking the current damage mitigated and if over a threshold declare infinite hits. Stopping is now determined if passing over a threshold of maximum number of iterations (number of times running the damage mitigation passes).

Guard skills were causing weird breakpointing behaviour due to iteration multiplier causing effective differences between speedup iterations and iteration multiplier iterations. This removes this from guard skill as the logic behind it doesn't make sense and causes undesirable behaviour.

This also includes a fix suggested by Regisle to fix recovery not being applied in future cycles leading to inefficient calculations on infinite hp recovery builds.

Steps taken to verify a working solution:

You now have partial hits before death.

Link to a build that showcases this PR:

https://pobb.in/vHR-vtTGMMrQ
https://pobb.in/5_CR0d50ihde
https://pobb.in/oFHTWXt9FMua
https://poe.ninja/pob/Kqz

Before screenshot:

After screenshot:

[Wires77]

LGTM, nice to have a fix for these