frontend: Snackbars are over the mission buttons on 'flight mode'/'map view'

[ArturoManzoli]

Current behaviour

Snackbars cover the mission action buttons on the map view. User has to wait 3s for it to auto-close and sometimes another one opens over it.

Expected or desired behaviour

Suggested solutions:

• Relocate mission buttons to a cluster (can also be movable by the user);
  or
• Relocate the snackbars to the top-center of the screen, right below the Alerter
  or
• Integrate snackbars with Alerter, adding colors/'severity levels' to it (Big task with important modifications to the system).
  and/or
• Add a close button to every snackbar;

Prerequisites

• I have checked to make sure that a similar request has not already been filed or fixed.