The lock_table() method needs database, ks and cf to find the table on
all shards. The same can be achieved with the help of global_table_ptr
thing that all the core callers already have at hand.
There's a test that doesn't have global table, but it can get one.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
Closesscylladb/scylladb#20139