Type add_message and add MessageLocationTuple

[DanielNoord]

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Type of Changes

	Type
✓	🔨 Refactoring

Description

This adds typing to add_message and adds a new NamedTuple to typing.py. I add a deprecation warning for Message, but I'm not sure if it is even necessary. Is Message part of the public API? If not I can remove it.

The type: ignore in tests/testutils/test_output_line.py will be fixed in a follow-up PR. OutputLine needs a little refactor to only accept int for column and line. This will bring it in line with all other code that references column or line, where those are also int.

[Pierre-Sassoulas]

I like this change. But maybe the msgid/symbol typing is something that should be done prior to this one ?

[cdce8p]

Looks good to me. @Pierre-Sassoulas Would you mind taking another look?

[Pierre-Sassoulas]

Thanks, you're almost single-handedly typing pylint :)