feat: cloning improvements, NPC clones

[shmakota]

Purpose of change (The Why)

You currently can't clone NPCs, but can clone everything else.
There's also some weird behavior with cloning-related content, this aims to mitigate some of that. Also cleans up some backend stuff related to cloning and extra item variables.

Describe the solution (The How)

Allows NPCs to be cloned. (to-do: require multiple samples or something, increase cloning time) Clones will copy gender, age, height, all traits that aren't specifically marked to be shed upon cloning or background traits, and physical stats at the time of cloning. Skills aren't copied as they are assumed to be learned, while stats are assumed to be physical improvements (maybe we can handwave it with some blob magic).

Swaps a few things over to use the requirements system, which makes using cloning vats with nearby items on the ground much cleaner and more straightforward.

Cloning stuff can be hard to understand for the survivor at the moment. Add some snippets and other hints towards it & how it functions in game. (to-do)

Describe alternatives you've considered

Not copying stats, or gender, etc. This can all be debated upon.

Testing

Do the generic cloning routine, but target an NPC or yourself. Confirm a clone pops out.

Additional context

Checklist

Mandatory

• I wrote the PR title in conventional commit format.
• I ran the code formatter.
• I linked any relevant issues using github keyword syntax like closes #1234 in Summary of the PR so it can be closed automatically.
• I've committed my changes to new branch that isn't main so it won't cause conflict when updating main branch later.

[DeinonychusDiscord]

This is exciting stuff. Looking forward to seeing how this could play out in future mission lines!