Login guarded routes

[tomheller]

Todo:

• [x] Move Menu into a better structure to support more screens
• [x] Add enter/leave animation for header bar to make the transition nicer

[tomheller]

Open for review before this is running too long.

Done:

• guarded login route
• Refactored menu to be more extensible
• Added initial settings page for jira integration
• Added animation for login

[tomheller]

Animations:

[ffriedl89]

🍔 nice!