tests: add test_distributed_loader_with_incomplete_sstables
tests: add test_distributed_loader_with_incomplete_sstables

Test removal of sstables with temporary TOC file,
with and without temporary sstable directory.

Temporary sstable directories may be empty or still have
leftover components in them.

Signed-off-by: Benny Halevy <23c997c90eb8537635e9392d48e7af1bf1b2ca22@scylladb.com>

scylladb/scylla,scylladb/scylla,scylladb/scylla,avikivity/scylla,scylladb/scylla,avikivity/scylla,avikivity/scylla