Hints on cross-view connections

[KjellMorgenstern]

Problem

If a connection is made in one view (e.g. Breadboard),
the other two views show a ratsnest line to indicate an unrouted connection.

New users often create connections in different views, e.g a wire in breadboard view,
and another wire in the schematic view.
Now, both views show the ratsnest lines that result from the connections made in the other view.
See the example #3685 (comment)

Proposed Solution

Set a priority view.
Default could be the first one used, or schematic, or breadboard? Preferences should have an option to change it.

If a wire is created in a non-priority view, a show an clickable information.

[failiz]

Related to #3743