Added context strings

front/src/components/playlists/PlaylistModal.vue

 <template>
   <modal @update:show="update" :show="$store.state.playlists.showModal">
     <div class="header">
-      <translate>Manage playlists</translate>
+      <translate :translate-context="'Popup/Playlist/Title/Verb'">Manage playlists</translate>
     </div>
     <div class="scrolling content">
       <div class="description">
         <template v-if="track">
-          <h4 class="ui header"><translate>Current track</translate></h4>
-          <translate
+          <h4 class="ui header"><translate :translate-context="'Popup/Playlist/Title'">Current track</translate></h4>
+          <translate :translate-context="'Popup/Playlist/Paragraph'"
             v-translate="{artist: track.artist.name, title: track.title}"
             :translate-params="{artist: track.artist.name, title: track.title}">
             "%{ title }", by %{ artist }
@@ -18,20 +18,20 @@
         <playlist-form :key="formKey"></playlist-form>
         <div class="ui divider"></div>
         <div v-if="errors.length > 0" class="ui negative message">
-          <div class="header"><translate>We cannot add the track to a playlist</translate></div>
+          <div class="header"><translate :translate-context="'Popup/Playlist/Error message.Title'">The track can't be added to a playlist</translate></div>
           <ul class="list">
             <li v-for="error in errors">{{ error }}</li>
           </ul>
         </div>
         </div>
-        <h4 class="ui header"><translate>Available playlists</translate></h4>
+        <h4 class="ui header"><translate :translate-context="'Popup/Playlist/Title'">Available playlists</translate></h4>
         <table class="ui unstackable very basic table">
           <thead>
             <tr>
               <th></th>
-              <th><translate>Name</translate></th>
-              <th class="sorted descending"><translate>Last modification</translate></th>
-              <th><translate>Tracks</translate></th>
+              <th><translate :translate-context="'*/*/Table.Label'">Name</translate></th>
+              <th class="sorted descending"><translate :translate-context="'Popup/Playlist/Table.Label/Short'">Last modification</translate></th>
+              <th><translate :translate-context="'*/*/Table.Label'">Tracks</translate></th>
               <th></th>
             </tr>
           </thead>
@@ -52,7 +52,7 @@
                   class="ui green icon basic small right floated button"
                   :title="labels.addToPlaylist"
                   @click="addToPlaylist(playlist.id)">
-                  <i class="plus icon"></i> <translate>Add track</translate>
+                  <i class="plus icon"></i> <translate :translate-context="'Popup/Playlist/Table.Button.Label/Verb'">Add track</translate>
                 </div>
               </td>
             </tr>
@@ -61,7 +61,7 @@
       </div>
     </div>
     <div class="actions">
-      <div class="ui cancel button"><translate>Cancel</translate></div>
+      <div class="ui cancel button"><translate :translate-context="'Popup/Playlist/Button.Label'">Cancel</translate></div>
     </div>
   </modal>
 </template>
@@ -113,7 +113,7 @@ export default {
     }),
     labels () {
       return {
-        addToPlaylist: this.$gettext('Add to this playlist')
+        addToPlaylist: this.$pgettext('Popup/Playlist/Table.Button.Tooltip/Verb', 'Add to this playlist')
       }
     },
     sortedPlaylists () {