Make a windows installer and winget package rinnable by non-admins

[sanzoghenzo]

Is your feature request related to a problem? Please describe.

Currently it is not possible to install gitui on windows with a regular user.

I suppose that being an admin is not an hard requirement to install this program, and it could be enough to install it to %localappdata%\programs.

Describe the solution you'd like

Since it seems that the cargo-wix, and in general the MSI packages, are not tailored for regular-users installs, I propose to switch to Innosetup and its github action.
This will create a .exe installer, that can handle both admin and non-admin installs.

The winget package definition should then be adapted to use this installer and to add the user scope for non-admin installations

Describe alternatives you've considered

Manually download the windows .tar.gz and put it in a folder in PATH.
I've just done it but it's not the best user experience having to do this manually each time.

Additional context

As I can see from Komac documentation, InnoSetup is supported and should detect the two scopes

[extrawurst]

@sanzoghenzo are you willing to work on this? i am not on windows, i could not move this forward myself

[sanzoghenzo]

I'll try 🤞