Feature/mypyconfig

[gimppa]

Description

Added mypy configuration to pyproject.toml, to make programming environments among developers more consistent.

This breaks github workflows, because of increased strictness of type checking. Updating typing is work in progress.

Type of change

• [x] New feature (breaking change which adds functionality)

Testing

• [x] Tests do not apply

[csc-felipe]

I think we can close this, as #790 includes these changes.