Add generic names to the applications in our menu who are only "branded names"

For example Brasero, Audacity, Thunderbird doesn’t tell you anything about what these applications do.

See https://lists.autistici.org/message/20200306.181628.1d401fc7.en.html

Proposals:

• Dasher → Dasher Text Input System
• Brasero → Brasero CD/DVD Burner
• Sound Juicer → Sound Juicer CD Ripper
• Audacity → Audacity Sound Editor
• OnionShare → OnionShare File Sharing
• Thunderbird → Thunderbird Email Client
• KeePassXC → KeePassXC Password Manager
• Inkscape → Inkscape Image Editor
• GtkHash → GtkHash Checksum Calculator
• Kleopatra → Kleopatra OpenPGP Encryption

We could try to suggest these changes upstream and otherwise patch the .desktop files ourselves.

The part of this work that's UX:debt and Core Work:Foundations Team is: cheap attempt to upstream this change to OnionShare, Thunderbird, and KeePassXC.

User research findings

• During #18762 (closed), P2 commented on not knowing what GtkHash and Kleopatra were.