[ENHANCEMENT] Activity indicators on UI tabs

[redactedscribe]

Please confirm these before moving forward.

• [X] I have searched for my feature proposal and have not found a work-in-progress/duplicate/resolved/discarded issue.
• [X] This improvement refers to an existing feature. If you want to suggest a new feature, please use this template.
• [X] This improvement is not a bug. If you want to report a bug, please use this template.

Describe the improvement

When the Discover Packages or Software Updates tabs are searching, the only way to know there is activity happening on either is by checking their tab and seeing the thin line which goes form left to right at the top indicating searching. If the Software Updates tab is updating packages, the thin line for activity appears at the bottom of the UI for each package updating.

Describe how this improvement could help users

If the square tabs on the left sidebar also showed some activity indicator, we'd know activity is happening regardless of which tab we're on.

[RonnyTNL]

+1

I use UniGet mainly "on demand" so when you open/start it you land on discover and have no idea if something is scanning or not, so some form of animation on the "Software updates" Icon would be very welcome, or perhaps loading the "Software updates" page as default might also resolve this as you then will notice the blue scan indicator.