Add hint translation to plus icon for creating posts

- Position adjustment of the news feed plus icon in hight, because in desktop browsers it intersects the footer.
- Added shadow to plus icon on the user page.

webapp/pages/index.vue

@@ -34,7 +34,7 @@
     </masonry-grid>
     <client-only>
       <ds-button
-        v-tooltip="{ content: 'Create a new Post', placement: 'left', delay: { show: 500 } }"
+        v-tooltip="{ content: $t('contribution.newPost'), placement: 'left', delay: { show: 500 } }"
         :path="{ name: 'post-create' }"
         class="post-add-button"
         icon="plus"
@@ -208,7 +208,7 @@ export default {
 .post-add-button {
   z-index: 100;
   position: fixed;
-  top: 98vh;
+  bottom: -5px;
   left: 98vw;
   transform: translate(-120%, -120%);
   box-shadow: $box-shadow-x-large;

webapp/pages/profile/_id/_slug.vue

@@ -206,7 +206,7 @@
               <ds-button
                 v-if="myProfile"
                 v-tooltip="{
-                  content: 'Create a new Post',
+                  content: $t('contribution.newPost'),
                   placement: 'left',
                   delay: { show: 500 },
                 }"
@@ -519,4 +519,7 @@ export default {
     }
   }
 }
+.profile-post-add-button {
+  box-shadow: $box-shadow-x-large;
+}
 </style>