Clean up the profession and scenario code

[sethsimon]

Changes:

• Make scenario::traitquery comprehensive: a trait is permitted by a scenario if and only if it returns true.
• Make scenario::get_permitted_professions public. Do away with scenario::profquery since that was only used to manually find out what scenario::permitted_professions would return.
• Remove a lot of dead code from scenario and some dead code from profession.
• Rename profession::locked_traits and scenario::locked_traits to is_locked_trait, rename profession::traits to get_locked_traits and add the scenario::get_locked_traits function. Character::add_traits is no longer the bottleneck in the starting_items test (see Never give new characters unusable food or clothing (part 1) #19924) since it doesn't need to loop over every trait that exists. With the mutation stuff not commented out, it still takes 110 minutes (down from 317 minutes), but it's a good start, and I'll address that in a future PR.
• Rename scenario::forbidden_traits and profession::forbidden_traits to is_forbidden_trait to be consistent with the above.

[Night-Pryanik]

Won't this remove the gender-specific scenario names?

[Zireael07]

haracter::add_traits is no longer the bottleneck in the starting_items test (see #19924) since it doesn't need to loop over every trait that exists. With the mutation stuff not commented out, it still takes 110 minutes (down from 317 minutes),

Yaaay!

[sethsimon]

Won't this remove the gender-specific scenario names?

Yes and no. You won't be able to declare it as

"name": {
    "male": "foo",
    "female": "bar"
}

anymore, but I couldn't find any scenarios that declared it like that, not even in mods. Instances where two names have two possible translations depending on the gender will still work as expected.

Yaaay!

Ha, almost. But no celebrating till it reaches an hour.