This commit adds the option -C/--class to the `dtc`
subcommand `delete-records`. With this option
`delete-records` attempts to delete all records
of the given class from the token-associated inbox,
the curated area, or from a specific inbox of the
collection.
Because non-curator access can only read the
(pid-based) union of records from the token-
associated inbox and the curated area, it cannot
determine which records are in the inbox and which
records are in the curated area. It assumes that
all records that are listed for a given class are
located in the inbox and tries to delete them all.
This might lead to warnings for those records that
are in the curated area, because deletion would
fail for them. The pids of all records that could
not be deleted are printed at the end of the
execution.
This restriction only holds if neither -c/--curated
nor `-i/--incoming` are defined.
