Open ZIP button, instance name in status bar, description scroll bar

[HebaruSan]

This pull request satisfies three minor GUI requests that came in recently.

Description scroll bar

Now if a module has a description (most don't), it will have a vertical scroll bar in case it's longer than the available space:

Fixes #2795.

Instance name in status bar

Now the status bar will show the game instance name and version:

German translation: Spielinstanz: whatever (KSP whatever)

Fixes #2807.

Open ZIP button on Contents tab of mod info

Now the Download button has an Open ZIP button next to it:

It becomes enabled when the module is cached:

Clicking it opens the ZIP file from the cache in your OS's archive browser (in this screenshot, whatever GNOME Shell uses):

German translation: ZIP öffnen

Fixes #2800.

[DasSkelett]

Now if a module has a description (most don't), it will have a vertical scroll bar in case it's longer than the available space:

It appears they always have scrollbars, even if the description is short enough to fit in the available space:

For the German translations, take ZIP öffnen (switch around) for the button,
and Spielinstanz: [...] (without space, and an 's' is missing).

[HebaruSan]

It appears they always have scrollbars, even if the description is short enough to fit in the available space:

Yeah, TextBox doesn't have a ScrollBars=Auto mode.