LPS-47402 Apply the liferay-staging:defineObjects tag

Hey Brian,

This is the first set of apply of the defineObjects tag Levente created. We've focused on the staging JSPs now, we'll follow up regarding the topic with other component leaders as well (site admin, layouts admin, etc) - so more to come.

We haven't deprecated the MenuTag's methods, because it has been recently moved there, so practically it's a new tag.

Thanks,

Máté