Feature suggestion: Improvements to relational editor selection

[emergency99]

As someone who works a lot with bus relations I would have two minor suggestions, that would speed up the fixing of routes:

1. When deleting one or more (in the relation list neighbouring) elements, the selection should select the entry beneath (or if there is none) the one above, so that a already selected way can be quickly inserted with the insert-arrow function without having to click onto the element in the relation element list.
2. There should be a button on the right side under the other insert selection into relation buttons for replacing selected elements in relation with current selection (on the map).

I hope such suggestions are allowed here and that I posted this in the right area.

KR RobinD. (emergency99)

[Woazboat]

See #21944 for point 2.