Use ChannelInfo class again

The previous non-Essentials archetype used the channel info class org.example.channels.WebsiteInfo. It makes it possible to edit a channel property "headerName" in the channel. This property is not used anymore.

I think the concept of using channel properties is very useful and should be part of the archetype. So do not remove the channel info class, but give it useful function.

Suggestions: add a logo that can be picked using the CM properties. Or add another stylesheet with a different bootstrap theme that can be picked from the assets section.