feat(linux): improve Support tab

[ermshiperete]

Comparing with the info on the Keyman for Windows diagnostic report:
https://help.keyman.com/knowledge-base/?id=40

Should we have a similar layout of the support tab across the products?

1. e.g. the center panel displays the Keyman logo, Keyman for Linux version? (without having to generate report to see it) and a link to the community site forum

2. Right panel having "Useful Links" to

• keyman.com
• "Diagnostics" which could then make use of the buttons you've made.
• Online help (help.keyman.com

Originally posted by @darcywong00 in #15576