Merge detail view and list view to one plugin "Tea list"

[lukaszuznanski]

Background: Having two separate plugins for the list and single view makes setting up the extension more work, and (for real-world extension) it also produces the problem of having to stop Google from indexing the single view page without any Tea UID in the URL, while allowing it to index the single view page with a Tea UID in the URL. News has this setup as well, but it also has a combined list/single view plugin that solves these problems.

[DanielSiepmann]

Combine with #1184 to demonstrate an Update Wizard and migrate existing setups.
#1184 needs to be done after this task.