Allow host:port selection

[holandes22]

• Add a settings section where the selection can be made
• Show selected hostname in a visible way at the sidebar
• User navigates to "/settings"
  • Is presented with a form to enter host:port values.
• User navigates to any other route (/pods, /pods/name, etc)
  • When entering the route, the model hook will try to fetch info from the host,. If an error occurs, show an error message

[holandes22]

Possible improvements:

• Show link to settings in error message if connection error
• Add a "test connection" feature in settings
  • If connection is good: show green
  • If connection is bad: show red
• Store user selection in cookie or localstorage

Opened #35 for this