added db query optimizations to playlists view, added caching

frontend/wailsjs/go/playlist/Service.d.ts

@@ -11,6 +11,8 @@ export function CreatePlaylistWithTracks(arg1:string,arg2:Array<string>):Promise
 
 export function GetAllPlaylists():Promise<Array<playlist.Summary>>;
 
+export function GetAllPlaylistsWithTracks():Promise<Array<playlist.WithTracks>>;
+
 export function GetPlaylistTracks(arg1:number):Promise<Array<playlist.Track>>;
 
 export function SetContext(arg1:context.Context):Promise<void>;

frontend/wailsjs/go/playlist/Service.js

@@ -18,6 +18,10 @@ export function GetAllPlaylists() {
   return window['go']['playlist']['Service']['GetAllPlaylists']();
 }
 
+export function GetAllPlaylistsWithTracks() {
+  return window['go']['playlist']['Service']['GetAllPlaylistsWithTracks']();
+}
+
 export function GetPlaylistTracks(arg1) {
   return window['go']['playlist']['Service']['GetPlaylistTracks'](arg1);
 }