Enable mypy checks for all error codes

[wochinge]

Maxime recently enabled mypy support for the first couple of issues. In our current setup we ignore certain typing issues as there are currently too many to tackle them all at once.

We should instead tackle them step by step. Parent issue.
This is the parent issue to make sure we tackle of the categories.

Definition of Done:

• enable mypy checks for for all error codes
• issues are fixed

[TyDunn]

@wochinge are there more error codes besides the ones referenced in this issue?

[wochinge]

Yep, a whole bunch:

disable_error_code = arg-type, assignment, var-annotated, return-value, union-attr,
    override, operator, attr-defined, index, misc, return, func-returns-value

[wochinge]

• argtype: 346 issues
• assignment: 164 issues
• var-annotated: 62 issues
• return-value: 97 issues
• union-attr: 91 issues
• override: 43 issues
• operator: 44 issues (handled by @twerkmeister)
• attr-defined: 53 issues
• index: 39 issues (handled by @wochinge )
• misc: 90 issues
• func-returns-value: 2 issues (handled by @wochinge )

[wochinge]

Starting with the index one and func-returns-value

[m-vdb]

@wochinge can we have the list of different errors and who's handling in the description of the issue instead of a comment below? I think it's easier for collaboration 😄

[m-vdb]

Also another thought @wochinge , it's possible that some of the remaining errors are not easy to fix and require some revamping (I remember hitting some issues with data structures). We might want to flag them (disable them locally and open follow-up ticket) and do them after the revamp. Just a thought 🤔

[wochinge]

Created issues for each remaining error code.