major redesign: move to rounded and extra spaceous UI

+ fix `play next` bug
+ add new folder banner image
+ add new now playing component
+ move to gray4 for accent color
+ increase image sizes, for clean UI

src/components/PlaylistView/Header.vue

@@ -12,14 +12,7 @@
     <div class="carddd">
       <div class="info">
         <div class="btns">
-          <PlayBtnRect
-            :source="playSources.playlist"
-            :store="usePStore"
-            :background="{
-              color: '#fff',
-              isDark: true,
-            }"
-          />
+          <PlayBtnRect :source="playSources.playlist" :store="usePStore" />
           <Option @showDropdown="showDropdown" :src="context.src" />
         </div>
         <div class="duration">