Add configurable delay for highlight_definitions

[Shatur]

Is your feature request related to a problem? Please describe.
I experience a blinky highlighting even if clear_on_cursor_move = false.

Describe the solution you'd like
It would be nice to have a configurable delay which doesn't depend on updatetime.

[asmodeus812]

Any news on that, would be a great feature, depending on updatetime seems like a rather weird idea.