the subcommand of "shard-of" does not support tablets yet. so let's
print out an error message, instead of printing the mapping assuming
that the sstables are distributed based on token only.
this commit also adds two more command line options to this subcommand,
so that user is required to specify either "--vnodes" or "--tablets"
to instruct the tool how the cluster distributes the tokens across nodes
and their shards. this helps to minimize the suprise of user.
this change prepares for the succeeding changes to implement the tablets
support.
the corresponding test is updated accordingly so that it only exercises
the "shard-of" subcommand without tablets. we will test it with tablets
enabled in a succeeding change.
Refs scylladb/scylladb#16488
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
3f8f1d7274