Use changeset tab for reinstall

[HebaruSan]

Problem

1. Install xScienceContinued (which will also install three dependencies)
2. Right-click it and select "Reinstall"
3. Click Yes in the confirmation popup
4. Click Continue on the recommendations screen
5. Install flow fails:
   

Cause

The changeset passed to the install flow for reinstallation includes the dependencies, so they're added to the resolver once as dependencies and then again later as user-selected, which triggers an exception.

Changes

• Now the reinstall option jumps to the changeset tab instead of popping up a confirmation dialog, so you can see what it's going to do
• Now the changeset tab saves the changeset it displays and passes it to the install flow upon confirmation, rather than re-calculating the changeset from the mod list
• Now the reinstall option generates a changeset that includes removing the depending/dependency mods but excludes installation of dependencies that will be pulled in automatically

After this, reinstallation succeeds for these mods. I also tried installing RP-1 express and re-installing some of it, and that worked as well. 🤞

Fixes #3725.

[HebaruSan]

@linuxgurugamer, when the build finishes, could you please take it for a test drive? It'll be under the Artifacts dropdown here:

https://github.com/KSP-CKAN/CKAN/pull/3726/checks

[techman83]

That all seems to make sense 🎉

[HebaruSan]

I need to review the pull requests that added the dependencies and dependent mods here before merging, to make sure we haven't broken some obscure known use cases...

• Use shared installer code in GUI and fix reinstall problems #2233 - just mentions re-installing dependent mods, which I've already covered
• Auto-uninstall auto-installed modules #2753 - added the auto-installed check but didn't say why (no documentation specific to reinstallation)

I guess we can rework this more freely than I thought.