Improve display of technical app info

Summary:
Improve display of app info in the following ways

• Display the app's caption in bold and apart from the other pieces to make it stand out more
• Group the pieces of info in a recognizable section
• Right-justify all the labels to make everything easier to parse
• Don't display the category with a link color since it's not a link

Test Plan:
Tested in KDE Neon. Before:

After:

(Ignore the duplicated categories in the sidebar; that's an unrelated issue tracked by https://bugs.kde.org/show_bug.cgi?id=388313)

Reviewers: apol, VDG, Discover Software Store

Reviewed By: apol, Discover Software Store

Subscribers: colomar, januz, alexeymin, plasma-devel

Tags: Plasma

Differential Revision: https://phabricator.kde.org/D9542