When doing some plugin related work, I discovered that the datastore API
has two issues:
- Error messages on startup of plugins init method when the datastore is
still completely empty: "Parsing '{datastore:[0:': token has no index 0: []"
- Data is escaped but not unwrapped again when sending and getting from
the API.
[ Removed xfail, it now passes! --RR ]
Closes: #5990