Add trainer based pokemon filtering

[tpolito]

Summary

This PR adds the ability to filter Pokémon sets by trainer name in the damage calculator. If "Only show imported sets" is checked that takes priority and will show over the trainer filter.

📸 Screenshots

Testing

My branch is deployed and testable here

[tpolito]

I was told via the discord that the Radical Red project isn't interested in contributions until after the next version release, however I already wrote the code, and figured at least people could weigh in on if this was a feature worth following up on after that version release.

Thoughts are welcome.

[quinnshultz]

I really welcome this addition. I started using the calculator the other day and immediately wanted this feature. I created a fork of this project to start implementing it, and I see you have already done so. Perfect! Let's see this added to the calculator please!