[Ability] Implement Tera Shell

[innerthunder]

What are the changes the user will see?

This implements the ability Tera Shell

Why am I making these changes?

Tera Shell is unimplemented, and my rewrite to Pokemon#getMoveEffectiveness (#3704) made it very easy to implement.

What are the changes from a developer perspective?

• data/ability: New pre-defend attribute FullHpResistTypeAbAttr changes the input type multiplier to 0.5 if it isn't already 0.5 or lower.
• field/pokemon: getMoveEffectiveness now applies FullHpResistTypeAbAttr as the last step (if the move is an attack).
• test/abilities/tera_shell.test New integration test suite for Tera Shell's effects on type effectiveness.

Screenshots/Videos

PokeRogue.-.Google.Chrome.2024-08-27.15-32-01.mp4

How to test the changes?

npm run test tera_blast

Checklist

• I'm using beta as my base branch
• There is no overlap with another PR?
• The PR is self-contained and cannot be split into smaller PRs?
• Have I provided a clear explanation of the changes?
• Have I considered writing automated tests for the issue?
• If I have text, did I make it translatable and add a key in the English locale file(s)?
• Have I tested the changes (manually)?
  • Are all unit tests still passing? (npm run test)
• Are the changes visual?
  • Have I provided screenshots/videos of the changes?

[frutescens]

[DayKev]

TIL 4 < 3