In this refactoring commit we remove the db::config::host_id
field, as it's hacky and duplicates token_metadata::get_my_id.
Some tests want specific host_id, we add it to cql_test_config
and use in cql_test_env.
We can't pass host_id to sstables_manager by value since it's
initialized in database constructor and host_id is not loaded yet.
We also prefer not to make a dependency on shared_token_metadata
since in this case we would have to create artificial
shared_token_metadata in many tools and tests where sstables_manager
is used. So we pass a function that returns host_id to
sstables_manager constructor.
b90011294d