Fix audio and video items in account gallery in web UI (#14282)

* Fix audio and video items in account gallery in web UI

- Fix audio items not using thumbnails
- Fix video items not using custom thumbnails
- Fix video items autoplaying like GIFs

* Change audio and video items in account gallery to autoplay when opened in web UI

* Fix code style issue

app/javascript/mastodon/features/audio/index.js

@@ -37,6 +37,7 @@ class Audio extends React.PureComponent {
     backgroundColor: PropTypes.string,
     foregroundColor: PropTypes.string,
     accentColor: PropTypes.string,
+    autoPlay: PropTypes.bool,
   };
 
   state = {
@@ -259,6 +260,14 @@ class Audio extends React.PureComponent {
     this.setState({ hovered: false });
   }
 
+  handleLoadedData = () => {
+    const { autoPlay } = this.props;
+
+    if (autoPlay) {
+      this.audio.play();
+    }
+  }
+
   _initAudioContext () {
     const context  = new AudioContext();
     const source   = context.createMediaElementSource(this.audio);
@@ -336,7 +345,7 @@ class Audio extends React.PureComponent {
   }
 
   render () {
-    const { src, intl, alt, editable } = this.props;
+    const { src, intl, alt, editable, autoPlay } = this.props;
     const { paused, muted, volume, currentTime, duration, buffer, dragging } = this.state;
     const progress = (currentTime / duration) * 100;
 
@@ -345,10 +354,11 @@ class Audio extends React.PureComponent {
         <audio
           src={src}
           ref={this.setAudioRef}
-          preload='none'
+          preload={autoPlay ? 'auto' : 'none'}
           onPlay={this.handlePlay}
           onPause={this.handlePause}
           onProgress={this.handleProgress}
+          onLoadedData={this.handleLoadedData}
           crossOrigin='anonymous'
         />