feat: 编辑器只读模式的subEditor支持返回 (#10959)

Co-authored-by: qinhaoyan <30946345+qinhaoyan@users.noreply.github.com>

packages/amis-editor-core/scss/editor.scss

@@ -136,6 +136,11 @@
     height: 100%;
     margin: 0;
   }
+  &-back {
+    position: absolute;
+    bottom: 46px;
+    left: 20px;
+  }
 }
 
 // 弹窗编辑器面板

packages/amis-editor-core/src/component/SubEditor.tsx

@@ -195,8 +195,14 @@ export class SubEditor extends React.Component<SubEditorProps> {
                     readonly={readonly}
                   />
                 )
+              },
+              readonly && {
+                type: 'button',
+                label: '返回编辑器',
+                className: 'subEditor-container-back',
+                onClick: () => store.closeSubEditor()
               }
-            ]
+            ].filter(Boolean)
           }
         : {
             type: 'tpl',