Currently it is required that sstables (in particular la/mx ones) are located at a valid path. This is required because `sstables::entry_descriptor::make_descriptor()` extracts the keyspace and table names from the sstable dir components. This PR relaxes this by using a newly introduced `sstables::entry_descriptor::make_descriptor()` overload which allows the caller to specify keyspace and table names, not necessitating these to be extracted from the path.
Tests: unit(dev), manual(testing that `scylla-sstables` can indeed load sstables from invalid path)
Closes#9466
* github.com:scylladb/scylla:
tools/scylla-sstable: allow loading sstables from any path
sstables: entry_descriptor::make_descriptor(): add overload with provided ks/cf
0d48c39cb3