chore: cleanup all test files

[Parkreiner]

No issue to link – this is just something I thought I could fix really quickly while working in the codebase.

Changes made

• Removed all unused imports, and made sure type imports were labeled correctly
• Updated all comparisons to be more strict
• Simplified loops to remove unneeded closure functions
• Removed all explicit any types
• Updated how strings were defined to follow general TypeScript best practices

Notes

• We definitely want some kind of linting setup for this repo. I'm going to bring this up when Blueberry has its next team meeting next week

[matifali]

@Parkreiner, all modules are merged. You may continue with the refactoring here,

[matifali]

We definitely want some kind of linting setup for this repo. I'm going to bring this up when Blueberry has its next team meeting next week

For linting, let us use biomejs, which is similar to a coder/coder. I am using biome vscode extension that does help catch these errors.