feat(mail): Add a setting to show the attachments above the mail body

UI/Templates/PreferencesUI/UIxPreferences.wox

@@ -721,6 +721,16 @@
               </md-checkbox>
             </div>
 
+            <div>
+              <md-checkbox
+                  ng-model="app.preferences.defaults.SOGoMailDisplayAttachmentAbove"
+                  ng-true-value="1"
+                  ng-false-value="0"
+                  label:aria-label="Show attachments above the message">
+                <var:string label:value="Show attachments above the message"/>
+              </md-checkbox>
+            </div>
+
             <div>
               <md-checkbox
                   ng-model="app.preferences.defaults.SOGoMailAutoMarkAsReadEnabled"