[BUG] Relationship lines overlap

[BaccanoMob]

Describe the bug
If a single key has a multiple relationships, the latest cardinality only shows on top.

To Reproduce
Steps to reproduce the behavior:

1. Add multiple relations on a single key

Expected behavior

1. The (1) or (n) bubble should have moved to side. That is, more the relation is on side there should be an indent
2. When hovered over proper relation cardinality should have been displayed

Possible solutions

1. Make relation lines draggable.
2. Hovering should highlight the correct relations between them.
3. Hovering should give a tooltip like box giving a short info on the relationship.

[BaccanoMob]

Also possibly add line colors to differentiate between 2 relations