Update mynah & handle auth follow up button

[ege0zcan]

Description

• Bumped mynah to latest version which fixes a few bugs:
  • Followup button showing up as text
  • Inline code suggestions having cut out borders
  • Text input scrolling issues
• This PR also adds logic so that Authentication buttons are shown on the right side of the UI

  License

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.