Fix wielding two-handed items with only one hand

[slarticodefast]

About the PR

Title
Thanks to @VerinSenpai for writing an integration test that found this bug.
To reproduce on master:

• Use the removehand command so that you only have one hand
• Spawn a baseball bat or mosin
• successfully wield it despite not having a free hand

Why / Balance

bugfix

Technical details

CanWield was comparing the number of freeable hands. However that included the hand the weapon was held in, which should not count as dropable when trying to wield it.
To fix this we add a new method to count free hands that can ignore a given item when counting.
We cannot just subtract 1 because the weapon itself might be unremoveable.

Media

Requirements

• I have read and am following the Pull Request and Changelog Guidelines.
• I have added media to this PR or it does not require an ingame showcase.

Breaking changes

Changelog
🆑

• fix: Fixed being able to wield two-handed weapons when having only one hand.

[VerinSenpai]

Yowza lmao

[VerinSenpai]

Guess I gotta fix my test afterall 😅

[Princess-Cheeseballs]

Not sure if we can just patch this out without breaking things. Monkeys have been able to wield melee weapons and guns for a while which I think is intentional?

In addition holoclowns use this to wield melee weapons too which will be more impactful.

Something something combat workgroup needs to chime in something something. Should be patched out though in favor of hand sizes like FSP suggested.

[slarticodefast]

Seems like a straight up bug to me to be able to wield two-handed weapons with only one hand.
And I don't think we should introduce an exception for that. That would be unintuitive. If holoclowns should be able to wield guns then they should have two hands or the guns should not require wielding.