Conditionally prevent damaging and spell auto-targeting Golem

[kphoenix137]

Alternative approach to the concept in #6881.
Fixes: #4352

When can a Golem be damaged?

By default, you are able to damage any Golem regardless of any settings or damage method.

In this PR, you are completely unable to damage your own Golem via any method or setting. For damaging Golems belonging to other players, it mirrors the same behavior as damaging other players, regardless of method or setting.

In the linked PR, there is no differentiation between owned/unowned Golems. Other than that, damaging Golems is completely consistent with damaging players based on options/settings.

The idea in this PR is to unify behavior between the ability to damage other players and other players' Golems, and to prevent damage to a player's own golem as a QoL improvement.

Regarding auto-targeting spells

I've revised the behavior of Chain Lightning, Bone Spirit, and Elemental to address the problem originally addressed in the issue before it was renamed. These spells now behave cohesively with the logic for damage in this PR, no longer targeting a Golem if it is unable to damage it. I left some comments for a potential future PR for if we should be preventing auto-targeting spells from targeting monsters they are unable to hit (teleporting monsters, immune monsters).

Potential problems

Problem: Unable to destroy own Golem with melee/arrows/spells
Solution: Casting Golem will no longer consume scroll/charge/mana if the spell is simply killing your Golem rather than creating a new one.
More solutions:

[ikonomov]

Yours makes more sense if we assume golems are like familiars, mine makes more sense if we assume golems are friendly summons. Whichever one works better for AJenbo, either one works for me.

[kphoenix137]

Yours makes more sense if we assume golems are like familiars, mine makes more sense if we assume golems are friendly summons. Whichever one works better for AJenbo, either one works for me.

Yours is viable. What I would change though is the usage of Friendly Fire for melee handling, as the logic is intended for spells/arrows, and not melee, and instead, use player.friendlyMode in its place. Your PR then should be fully consistent across the board (or across the table I made, I guess :D). It would then be the same as mine other than the fact mine stops all damage to player's own golem no matter what.

[ikonomov]

Right you are, changed.

[kphoenix137]

@ikonomov updated the PR description to represent your changes.

[kphoenix137]

If no damage to own Golem as seen as too heavily a change to gameplay, I think it would still be adequate to mirror ikonomov's PR along with the other additions in this PR.

Additionally, it's worth considering never targeting Golems with spells that auto-target monsters. It's clear that in the original code, Guardians will never attack a Golem on purpose no matter what. Perhaps the same logic should be adopted for Chain Lightning, Elemental, and Bone Spirit?