Optimize page loading by caching playlist items

[akdasa]

optimization: there is no reason to fetch all playlist items again and agian, we can cache it

lectorium-mobile/modules/lectorium/playlist/containers/TracksSearchResult.vue

Lines 62 to 68 in e8d423a

	const [
	tracks,
	playlistItems
	] = await Promise.all([
	library.tracks.getAll(), // TODO: filter by query
	userData.playlistItems.service.getAll()
	])