fix: 0.3.9 launch review (#4076)

* fix: cursor away doesn’t save the change. This behavior is inconsistent with the rest

* fix: emoji doesn’t show fully

* chore: set the default header text style to bold

* fix: add missing divider in time option

* fix: update placeholder cover color

* fix: background color of the change cover button

* fix: remove redundant padding

* fix: use done action instead of return

* fix: incorrect font size used in board and editor

* feat: update appflowy-editor

* fix: document freeze and the toolbar was invisible when hovering the align icon that in the toolbar

* fix: snackbar text is invisiable

* feat: padding of add icon button should be aligned the block

* chore: update icon

* fix: ci issues

* feat: add time picker

frontend/appflowy_flutter/lib/plugins/base/icon/icon_picker.dart

@@ -141,7 +141,7 @@ class _RemoveIconButton extends StatelessWidget {
       child: FlowyButton(
         onTap: onTap,
         useIntrinsicWidth: true,
-        text: FlowyText(
+        text: FlowyText.small(
           LocaleKeys.document_plugins_cover_removeIcon.tr(),
         ),
         leftIcon: const FlowySvg(FlowySvgs.delete_s),