Practice Tiles should have different styling to indicate practice over activity

[xronosuf]

Currently there is no obvious styling to differentiate an activity versus practice file in the pdf. We should have some kind of styling, either in the title or something in the header title placement to indicate when content is generated via a \practice command rather than an \activity command. This could (should?) be captured via a hook, so that authors can adjust the styling if desired (with a nice default styling for those that don't care obviously)

NOTE: This is one of the issues noticed via the pdf from the "all examples" repo compilation as part of the full project audit I'm doing.

[bartsnapp]

In the past I've made custom \practiceStyle tags for the xourse file