Make transform return the same type as input

[haarisr]

Description

Transform call currently returns a new type TypeTransformInput. This PR makes a generic type bound by the original TypeTransformInput so that type checkers know the same type is being returned.

Checklist

• I have read the CONTRIBUTING docs and have a developer setup (especially important are pre-commitand pytest)
• Non-breaking change (would not break existing functionality)
• Breaking change (would cause existing functionality to change)
• Tests added or modified to cover the changes
• Integration tests passed locally by running pytest
• In-line docstrings updated
• Documentation updated, tested running make html inside the docs/ folder
• This pull request is ready to be reviewed

[fepegar]

Thanks for your contribution, @haarisr!

[fepegar]

@allcontributors please add @haarisr for code

[allcontributors]

@fepegar

I've put up a pull request to add @haarisr! 🎉