[MM-22872] fix(messaging): DM list not scrolling when you press the up/down arrow keys (#29565)

* Set 'forwardRef' to 'true'

The Redux wrapper component not forwarding the ref to the parent resulted in the selected item ref being null.

* Add DM list test case

This test ensures the DM list scrolls items out of view into view when a user navigates using the Up and Down arrow keys.

* test(dm list): add zephyr test case number

---------

Co-authored-by: Mattermost Build <build@mattermost.com>

webapp/channels/src/components/more_direct_channels/list_item/index.ts

@@ -15,4 +15,4 @@ function mapStateToProps(state: GlobalState) {
     };
 }
 
-export default connect(mapStateToProps)(ListItem);
+export default connect(mapStateToProps, null, null, {forwardRef: true})(ListItem);