[Glitch] Add alt text for preview card thumbnails

Port 8da99ffb0d to glitch-soc

Signed-off-by: Claire <claire.github-309c@sitedethib.com>

app/javascript/flavours/glitch/features/explore/components/story.jsx

@@ -23,6 +23,7 @@ export default class Story extends PureComponent {
     author: PropTypes.string,
     sharedTimes: PropTypes.number,
     thumbnail: PropTypes.string,
+    thumbnailDescription: PropTypes.string,
     blurhash: PropTypes.string,
     expanded: PropTypes.bool,
   };
@@ -34,7 +35,7 @@ export default class Story extends PureComponent {
   handleImageLoad = () => this.setState({ thumbnailLoaded: true });
 
   render () {
-    const { expanded, url, title, lang, publisher, author, publishedAt, sharedTimes, thumbnail, blurhash } = this.props;
+    const { expanded, url, title, lang, publisher, author, publishedAt, sharedTimes, thumbnail, thumbnailDescription, blurhash } = this.props;
 
     const { thumbnailLoaded } = this.state;
 
@@ -50,7 +51,7 @@ export default class Story extends PureComponent {
           {thumbnail ? (
             <>
               <div className={classNames('story__thumbnail__preview', { 'story__thumbnail__preview--hidden': thumbnailLoaded })}><Blurhash hash={blurhash} /></div>
-              <img src={thumbnail} onLoad={this.handleImageLoad} alt='' role='presentation' />
+              <img src={thumbnail} onLoad={this.handleImageLoad} alt={thumbnailDescription} title={thumbnailDescription} lang={lang} />
             </>
           ) : <Skeleton />}
         </div>

app/javascript/flavours/glitch/features/explore/links.jsx

@@ -67,6 +67,7 @@ class Links extends PureComponent {
             author={link.get('author_name')}
             sharedTimes={link.getIn(['history', 0, 'accounts']) * 1 + link.getIn(['history', 1, 'accounts']) * 1}
             thumbnail={link.get('image')}
+            thumbnailDescription={link.get('image_description')}
             blurhash={link.get('blurhash')}
           />
         ))}

app/javascript/flavours/glitch/features/status/components/card.jsx

@@ -178,7 +178,8 @@ export default class Card extends PureComponent {
         dummy={!useBlurhash}
       />
     );
-    let thumbnail = <img src={card.get('image')} alt='' style={thumbnailStyle} onLoad={this.handleImageLoad} className='status-card__image-image' />;
+    const thumbnailDescription = card.get('image_description');
+    const thumbnail = <img src={card.get('image')} alt={thumbnailDescription} title={thumbnailDescription} lang={language} style={thumbnailStyle} onLoad={this.handleImageLoad} className='status-card__image-image' />;
     let spoilerButton = (
       <button type='button' onClick={this.handleReveal} className='spoiler-button__overlay'>
         <span className='spoiler-button__overlay__label'>