Harmonize reset buttons in "My Settings"

Harmonize reset buttons in "My Settings"

- Rename both buttons to a single word as it is clear where they belong
  to. Use "Reset" instead of "Clear" as you can rather "Reset a saved
  user name" than "Clear a layout".
- Use container instead of panels as they are simpler (e.g. no "border:
  false" necessary) and sufficient.
- Align the buttons at the right for visual appeal.
- Use title case for the user name label for consistency.

Signed-off-by: Dominic Jäger <d.jaeger@proxmox.com>