feat: Add Lua bindings to toggle mutations on/off

[karxi]

Checklist

Required

• I wrote the PR title in conventional commit format.
• I have committed my changes to new branch that isn't main so it won't cause conflict when updating main branch later.

Purpose of change

Current Lua bindings for Creature objects are somewhat incomplete. In particular, there is no way to cleanly disable a mutation, or enable one at all.

Describe the solution

Added a couple of lines in src/catalua_bindings_creature.cpp. Now we can do this:

muti = MutationBranchId.new("WEB_WEAVER")       -- pick a disruptive example
gapi.get_avatar():set_mutation(muti)            -- force it onto the player
gapi.get_avatar():activate_mutation(muti)       -- weave a tangled web
gapi.get_avatar():deactivate_mutation(muti)     -- free the player from themselves

I also added a few lines in src/mutation.cpp. Its corresponding activate/deactivate_mutation functions now check if the player has the necessary target—i.e., they have the mutation and it is (in)active.

Describe alternatives you've considered

The alternative looks roughly like this:

muti = MutationBranchId.new("WEB_WEAVER")   -- pick a disruptive example
gapi.get_avatar():set_mutation(muti)        -- force it onto the player
-- Close console, open mutations menu, activate Web Weaver per example
gapi.get_avatar():unset_mutation(muti)      -- unceremoniously remove mutation
gapi.get_avatar():set_mutation(muti)        -- give mutation back, now off by default

It is exactly as awful as it seems.

Testing

See "Describe the solution", but also:

gapi.get_avatar():deactivate_mutation(MutationBranchId.new("BIOLUM1"))
gapi.get_avatar():activate_mutation(MutationBranchId.new("BIOLUM2"))

These should no longer error on a character without the specified mutations.

Additional context

If there's any code that needed to activate mutations multiple times without de-'power'-ing them...sorry! I don't know of anything else this could possibly break.

[RoyalFox2140]

This can't be easily or effectively tested because our maintainer base doesn't script in lua. It looks like all the other lua hooks though. Given that it looks fine and it's primarily a mod problem this should be safe.

[RoyalFox2140]

Weep at this black magic with me, Chaos.

[chaosvolt]

I cri. Currently still out on laptop, I'll see if I can get home soon and compile-test but I have fuck-all idea how to fiddle with LUA currently. :D

[RoyalFox2140]

I cri. Currently still out on laptop, I'll see if I can get home soon and compile-test but I have fuck-all idea how to fiddle with LUA currently. :D

Scarf says we can run in the lua console that we apparently have built into the game, and the testing code is commands we can run.

[chaosvolt]

1. Compiled and load-tested.
2. Tried the first LUA command suggested, it correctly does nothing when used on a character without Weak Photophore.
3. Gave myself that trait and tried again. No weird errors on trying to deactivate an inactive mutation, does (silently) deactivate the mutation if you turn it on first.

Minor oddity: Deactivating an active mutation with the LUA doesn't print the normal deactivation message.