Moved absorb logic from EntityEffectManager to FormulaHelper

[dakoller123]

Hey Guys!

I'd like to attempt another PR regarding spell absorb. 4 years ago it was closed due to feature freeze. Today I re-forked unity and re-did the whole change from scratch, I've also made an experimental dfumod that overrid the absorb effect.

What has changed:

• Moved TryAbsorbtion method from EntityEffectManager to FormulaHelper, alongside it's helper methods
• TryAbsorption now returns the absorbed spell point count instead of a bool and an out variable
• TryAbsorption has the target caster entity and the absorb incumbent effects as function parameters now so its side effect-free
• Tiny refactor around the usage of TryAbsorb, the same 'if bundletype is spell' was reused 3 times

What was out of scope:

• Moving Reflection and Resistance to the FormulaHelper in a similar fashion. Once this PR is approved I might do that as well

How it was tested:

• I built my own binaries from my fork and used an experimental version of Mighty Magick mod where I overrid the formula. It all worked as expected.

Link to the old PR for reference:
#2179