[Balance] Make sure trainers are using fully evolved Pokémon by gym 3

[DayKev]

What are the changes?

Starting at the third gym, trainers will no longer have Pokémon that aren't fully evolved (except for intentionally weak trainers like the Breeder class).

Why am I doing these changes?

Request from balance team member Blitzy (and also because it's silly that the Rival fight on 95 could have an unevolved Growlithe or Feebas).

What did change?

Generated Pokémon for trainer teams are forced to be fully evolved starting at wave 80 (the third gym). A new currentWave parameter was added to getSpeciesForLevel() to facilitate this check.

How to test the changes?

Start at wave 95 a few times and check the Rival's party via the console.

Checklist

• [x] I'm using beta as my base branch
• [x] There is no overlap with another PR?
• [x] The PR is self-contained and cannot be split into smaller PRs?
• [x] Have I provided a clear explanation of the changes?
• [x] Have I considered writing automated tests for the issue?
• [x] Have I tested the changes (manually)?
  • [x] Are all unit tests still passing? (npm run test)
• ~[ ] Are the changes visual?~
  • ~[ ] Have I provided screenshots/videos of the changes?~