[ENG-6567][ENG-6598] Fix dropdown placement for mobile (#2408)

* Fix dropdown placement for mobile

* a11y fix for items per page dropdown

Author: futa-ikeda

app/institutions/dashboard/-components/institutional-users-list/styles.scss

@@ -139,7 +139,6 @@
 
     &.mobile {
         max-width: none;
-        right: 100%;
     }
 }
 

lib/osf-components/addon/components/adjustable-paginator/template.hbs

@@ -1,12 +1,15 @@
 <span local-class='paginator__control'>
     <div local-class='paginator__select-wrapper'>
-        <select title={{t 'paginator.itemsPerPage'}} local-class='paginator__select' onchange={{action this.onPageSizeChange value='target.value'}}>
-            {{#each this.pageSizeOptions as |page_size_option|}}
-                <option value={{page_size_option}} selected={{eq page_size_option this.selectedPageSize}}>
-                    {{t 'paginator.itemsPerPage'}} {{page_size_option}}
-                </option>
-            {{/each}}
-        </select>
+        <label>
+            {{t 'paginator.itemsPerPage'}}
+            <select local-class='paginator__select' onchange={{action this.onPageSizeChange value='target.value'}}>
+                {{#each this.pageSizeOptions as |page_size_option|}}
+                    <option value={{page_size_option}} selected={{eq page_size_option this.selectedPageSize}}>
+                        {{page_size_option}}
+                    </option>
+                {{/each}}
+            </select>
+        </label>
     </div>
 </span>