add bundle install support

[kolunmi]

[AlexanderVanhee]

Current issues:

• Only opens the page on the second attempt of opening a bundle
• Both bundle and remote entry gets added to the cache
• Removing just after installing does not update the "installed" property of the entry.

Would it be easier for the backend to just have a separate dialog to install the bundle? It's something that I want to do in the future anyway...

[AlexanderVanhee]

It seems to work better now, but the bug where the remove button does not disappear when removing just after install still persists.

[AsciiWolf]

Don't forget to add the BzBundleInstallDialog to POTFILES.in. ;-)

[kolunmi]

Screencast.From.2026-05-04.03-35-54.mp4

now we just need to make the UI pretty

[kolunmi]

Gonna make the UI mockup implementation a separate pr. For now I want the technical improvements in main