Briefcase uninstall

[lrandersson]

Description

Needs to be rebased once #1133 is merged.

Checklist - did you ...

• Add a file to the news directory (using the template) for the next release's release notes?
• Add / update necessary tests?
• Add / update outdated documentation?

[lrandersson]

This approach is a bit different from how we currently handle run_installation.bat. I'd like to hear some feedback/thoughts on what you (the reviewer) thinks.

I went with this class-based approach because I think it's better in terms of future maintenance and also makes unit testing very convenient, and easy to read. All the code for it is in one place and easy to follow. I think most of constructor is written in a "scripted" approach and I think that works for small projects, but for larger projects it can quickly become cumbersome. I would argue the project could benefit from a more object-oriented approach in general.
Moreover, simplifying the testing would be a good win for the project. One of the major pain points in constructor is the difficulty of running the tests locally, and to do it fast and "as close to production" as possible.

If we don't wanna go with this approach, it wouldn't take a lot of effort to simply add a pre_uninstall.bat and change the implementation, but I would propose we add something similar also for run_installation.bat (I'm happy to do that update if we go with it).

This can also be expanded upon at a later point, for instance by changing the lists of commands to jinja-based templating.