make tracks view wrap-around less surprising

[ronso0]

Feature Description

#11090 added wrap-around to the tracks view when it is navigated with either Up/Down keys or with a controller.
As helpful as this, for example when having the tracks sorted by key, I find it usually surprising / confusing because there's no clear feedback when approaching the top/bottom of the list.

So far two helpers came to mind:

1. delay the wraparound 524cbc7
   when pressing Up/Down repeatedly, require a keypress pause of 1 second before wrapping around. 1 second is just a guess, will probably adjust that after testing with my controller.
   also, this can be adjusted to work with one timer, but

2. show more surrounding lines (3) when moving 9d39314
   Applied for Up, Down, PageUp & PageDown.
   With that, there's more context and the wrap-around is to be expected when the cursor moves to the first/last row.

For now, these two commits combined work fine for me. If anyone wants to polish it, for example make the number of lines above/below depend on the total of visible lines, feel free to cherry-pick these commits.