New: Allow Import to update existing Custom Formats

Fixes #6178

frontend/src/Settings/CustomFormats/CustomFormats/EditCustomFormatModalContent.css

@@ -4,6 +4,11 @@
   margin-right: auto;
 }
 
+.rightButtons {
+  justify-content: flex-end;
+  margin-right: auto;
+}
+
 .addSpecification {
   composes: customFormat from '~./CustomFormat.css';
 

frontend/src/Settings/CustomFormats/CustomFormats/EditCustomFormatModalContent.js

@@ -198,6 +198,7 @@ class EditCustomFormatModalContent extends Component {
           </div>
         </ModalBody>
         <ModalFooter>
+          <div className={styles.rightButtons}>
             {
               id &&
                 <Button
@@ -209,15 +210,13 @@ class EditCustomFormatModalContent extends Component {
                 </Button>
             }
 
-          {
-            !id &&
             <Button
               className={styles.deleteButton}
               onPress={this.onImportPress}
             >
               {translate('Import')}
             </Button>
-          }
+          </div>
 
           <Button
             onPress={onModalClose}