Display a message if the invitations list is empty.

For #887

src/i18n/en_US.json

@@ -793,6 +793,7 @@
   "No instance to reject|Reject instance|Reject {number} instances": "No instance to reject|Reject instance|Reject {number} instances",
   "No instance to remove|Remove instance|Remove {number} instances": "No instances to remove|Remove instance|Remove {number} instances",
   "No instances match this filter. Try resetting filter fields?": "No instances match this filter. Try resetting filter fields?",
+  "No invitation yet. Create a new invitation with the button \"New invitation\".":"No invitation yet. Create a new invitation with the button \"New invitation\".",
   "No languages found": "No languages found",
   "No location yet": "No location yet",
   "No member matches the filters": "No member matches the filters",

src/i18n/fr_FR.json

@@ -793,6 +793,7 @@
   "No instance to reject|Reject instance|Reject {number} instances": "Aucune instance \u00e0 rejeter|Rejeter une instance|Rejeter {number} instances",
   "No instance to remove|Remove instance|Remove {number} instances": "Pas d'instances \u00e0 supprimer|Supprimer une instance|Supprimer {number} instances",
   "No instances match this filter. Try resetting filter fields?": "Aucune instance ne correspond \u00e0 ce filtre. Essayer de remettre \u00e0 z\u00e9ro les champs des filtres\u00a0?",
+  "No invitation yet. Create a new invitation with the button \"New invitation\".":"Il n'y a pas encore d'invitation. Créez une nouvelle invitation avec le bouton \"Nouvelle invitation\".",
   "No languages found": "Aucune langue trouv\u00e9e",
   "No location yet": "Localisation non renseign\u00e9e",
   "No member matches the filters": "Aucun\u00b7e membre ne correspond aux filtres",

src/views/Group/GroupInvitations.vue

@@ -51,13 +51,15 @@
           groupInvitationsError?.message
         }}</o-notification>
       </div>
-      <div
-        v-else-if="
-          groupInvitationsResult &&
-          groupInvitationsResult.listInvitations.length
-        "
-      >
-        <o-table :data="groupInvitationsResult.listInvitations">
+      <div v-else-if="groupInvitationsResult">
+        <div v-if="!groupInvitationsResult.listInvitations.length">
+          <o-notification type="info" variant="info">{{
+            t(
+              'No invitation yet. Create a new invitation with the button "New invitation".'
+            )
+          }}</o-notification>
+        </div>
+        <o-table v-else :data="groupInvitationsResult.listInvitations">
           <o-table-column
             field="label"
             :label="t('Label')"