Fixes to enchantment armor with mutations

[bombasticSlacks]

Summary

Bugfixes "Further fixes to enchantment armor with mutations"

Purpose of change

Some mutations were still failing to apply their effects when worn with the enchantment system. An example that works are the traits from my #53567 which just give a simple "weight_capacity_modifier": 1.1. This shouldn't be the case, all mutations should apply.

Describe the solution

It seems that traits like this are queried through the cached_mutations vector in a pretty convoluted call stack. To the place I migrated stuff for safety in #54852 I've also added a call to update the cached_mutation character vector identically to how it is when gaining/losing a mutation normally.

Describe alternatives you've considered

Testing

I tested with this + my nomad stuff from #53567.

[
  {
    "type": "mutation_type",
    "id": "Equipment"
  },
  {
    "type": "mutation",
    "id": "well_distributed",
    "name": { "str": "Well Distributed Gear" },
    "points": 0,
    "description": "You are wearing equipment that helps to distribute weight allowing you to carry more.",
    "valid": false,
    "purifiable": false,
    "types": [ "Equipment" ],
    "weight_capacity_modifier": 1.1
  }
]

and add to an armor

"relic_data": { "passive_effects": [ { "has": "WORN", "condition": "ALWAYS", "mutations": [ "well_distributed" ] } ] },

Additional context

I don't think this can possibly break anything but I don't fully understand all of the mutation system under the hood.