Tweak the profile manager dialog

- Show profile path as tooltip, for the fallback profile show
  "Built-in/hardcoded"
- Add " [Read-only]" to the Default/fallback profile name
- Make the font of the current default profile bold to match the menu
  in 'File -> New Tab'
- Change the text added to the current default profile to " default", i.e.
  lowercase, to differentiate between it and the fallback profile, which
  is called Default

Fix indentation in switch/case statements.