Extend modular logic to allow for more configuration setups

[Cerapter]

This PR extends the usage of modular beyond just changing the damage type to B, P, or S.

• The existing B-P-S switcher modular trait is kept as-is so that no migration is necessary.
• Several parts of the code where it is assumed that the modular selection can only be a damage type is changed to be just a string (which should be the key of the modular config, see below).
• A new PF2E config is introduced, called modularConfigs, that matches traits to sets of modular configs, which they themselves match a string key to an optional damage type (optional because SF2's shock truncheon), an array of traits (that can be empty), and a label that is effectively the localisation of the key of the config.
• Added the modular trait to Switchscythe, with the Switchscythe-specifics.

Though not present here, I've tested this with a few setups, like having a thrown trait in the modular trait, or with combination weapons.
Here's a visual demonstration:

modular_showcase.mp4

There are a few spots where I'm not sure if I approached this correctly -- WeaponTraitToggles's applyChanges() and WeaponPF2e's toThrownUsage(), I'm not too sure about, the latter I think might benefit more from a reorganisation from when data is handled? But I don't know enough about the system to feel out how it would best be reorganised, so consider this a "half-draft" PR.