Frank element hover hiding improvements

I think it is good. Do you think it would be hard to only show the forward of the hovered pipe to an exit and all when hovering over the exit?

_Originally posted by @philipsens in https://github.com/frankframework/flow/issues/574#issuecomment-4904260338_

Start by exploring the hover behavior in the Flow Studio and Editor, since the issue does not name a file, entry point, or test. Clarify whether hovering a pipe should reveal only its forward path to an exit and what should be shown when hovering an exit; done means the intended elements consistently appear and unrelated elements remain hidden.

Written by the indexing model from the issue text.