Feature: Add ability to jump to search result

[JohnMitchell04]

Currently, there's no way to jump to a search result within a playlist without first playing the song and using JumpToCurrentTrackInContext. This PR adds the ability to jump directly to any search result in a playlist. After searching, highlight a result and press C-j to jump to its location in the playlist.

The default keybind is C-j, which overlaps with MovePlaylistItemDown. Whilst, the two don't conflict during search, I recognise this may not be desirable, so I can change the default if desired.