Begin mypy type-checking

[Kilo59]

Begin minimal type-checking of the codebase as part of the effort to export type hints.

• Add type hints to improve codebase readability and enable static type checking #203
• Add make types item
• Add types to make tests step that runs in ci
• Type checking of select modules
  • utils
  • compat
  • exceptions

Will followup this up to add annotations to remaining modules.

[mindflayer]

I am sorry it took a while, I had to find some time to invest in the CI for being able to run tests on external PRs.
It looks like mypy is not happy about the way I am dealing with location when made of just a str.
I'll come back to you with a fix.

[sonarcloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
No data about Coverage
No data about Duplication

See analysis details on SonarCloud

[coveralls]

coverage: 98.59% (-0.2%) from 98.818%
when pulling f0e5442 on Kilo59:main
into 389d95e on mindflayer:main.

[mindflayer]

Merged, we still lack a pre-commit hook for mypy.