Redesign Connections tab

[GriffinRichards]

Redesigns the Connections tab, with a few goals in mind:

• Give direct access to edit any map connection. Prior to this you had to select the connection in the map to edit it, which is a little inconvenient and in some niche cases impossible.
• Properly support maps connected to themselves (this was very buggy and prone to crashing)
• Add a way to view how Dive/Emerge maps line up with the current map
• Close Improve the connection tab #486
• Close Allow for easy switching to dive and emerge maps #595