Highlight broken links of the graph

[ddelpiano]

Acceptance criteria:

• when building a graph with the path builder, if the graph does not connect to origin or/and destination highlight ONLY the last broken link(s) (in both directions if not connected to both origin and destination).
• display the nodes part of this incomplete graph in the canvas but do not connect them until that branch is correctly connected to at least one origin and at least one destination.
• There could be multiple incomplete graphs (due to branching), in this case highlight all the last broken links in the path builder as per screenshot above.

The estimate for this is 12 hours.

[ddelpiano]

Acceptance criteria:

• when building a graph with the path builder, if the graph does not connect to origin or/and destination highlight the last broken link(s) (in both directions if not connected to both origin and destination).
• display the nodes part of this incomplete graph in the canvas but do not connect them until that branch is correctly connected to at least one origin and at least one destination.

The estimate for this is 12 hours.