On the default Space Page, merge Things and Tags

Summary: By default, a Space's front page shows the hierarchy of all Things, followed by lists of the Tags used for each Thing. Having the two separate lists makes sense from a programmer's perspective, but from a typical end user's viewpoint it's just confusing. These two lists should be merged.

In other words, in Dad's wine inventory, the Tags used for "Winery" should be listed under the "Winery" Model in the main hierarchy. We've gone to substantial work to make Tags behave like default Things; we should continue this process.

There should probably be a visual distinction between names that are actually Things vs. ones that are just Tags, but it probably doesn't have to be big and bold.

This will likely require some QL enhancements, in order to merge the two lists, which are of different types. But that's probably a good enhancement.