The test checks that
- for non-system keyspace datadir and its staging/ and upload/ subdirs
are created when the table is created _and_ that the directory is
re-populated on boot in case it was explicitly removed
- for system non-virtual tables it checks that the same directory layout
is created on boot
- for system virtual tables it checks that the directory layout doesn't
exist
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>