Added Difficulty Fallback for Trainer Slides

[pkmnsnfrn]

Description

Adds fallback behavior for Trainers to use DIFFICULTY_NORMAL Trainer Slides when not defined for the player's current difficulty

Trainer Slides arrays match the Trainer structs, allowing developers to create Trainer Slides variants for each level of difficulty.

For all other difficulty related features, if the Trainer was not defined for the current difficulty level, the game would fall back to whatever was defined for the trainer on DIFFICULTY_NORMAL.

This fallback behavior did not exist for Trainer Slides - if the player was on DIFFICULTY_HARD and battled TRAINER_WALLACE who had Slides defined for DIFFUCLTY_NORMAL but not DIFFICULTY_HARD, then nothing would play.

This PR adds this fallback behavior.

Discord contact info

pkmnsnfrn

There is a discussion thread.

[pkmnsnfrn]

Specifically asking Jasper to review because he pointed out the need for the feature and I want to make sure it works as he expects

[hedara90]

Didn't the trainerslides have difficulty fallback before the refactor?
I remember talking about it during the difficulty review.

[pkmnsnfrn]

Didn't the trainerslides have difficulty fallback before the refactor? I remember talking about it during the difficulty review.

https://discord.com/channels/419213663107416084/1207720924414087168/1323390084401332337

I don't remember if you actually PR'd a fix but I don't think you did

but even so, this PR adds it either way /shrug

[hedara90]

I can't get the fallback to work when fighting Tiana on Easy with a team for easy but no slide for that difficulty.

[pkmnsnfrn]

I can't get the fallback to work when fighting Tiana on Easy with a team for easy but no slide for that difficulty.

Stupid errors on my side added late. Fixed now.

[hedara90]

Can confirm that the fallbacks work properly now.