LPS-46019 - navigation dropdown caret disappears after editing page name

Hi @jonmak08,

Attached is an update for https://issues.liferay.com/browse/LPS-46019.

Based on Nate's recommendation in https://github.com/natecavanaugh/liferay-portal/pull/2356, I tried to use the Liferay.Data.NAV_ITEM* design pattern so that a theme developer can override if they want other things inside the nav item.

Please let me know if there are any issues.

Thanks!