To add a sharded service to the cql_test_env one needs to patch it in 5 or 6 places
- add cql_test_env reference
- add cql_test_env constructor argument
- initialize the reference in initializer list
- add service variable to do_with method
- pass the variable to cql_test_env constructor
- (optionally) export it via cql_test_env public method
Steps 1 through 5 are annoying, things get much simpler if look like
- add cql_test_env variable
- (optionally) export it via cql_test_env public method
This is what this PR does
refs: #2795Closes#15028
* github.com:scylladb/scylladb:
cql_test_env: Drop local *this reference
cql_test_env: Drop local references
cql_test_env: Move most of the stuff in run_in_thread()
cql_test_env: Open-code env start/stop and remove both
cql_test_env: Keep other services as class variables
cql_test_env: Keep services as class variables
cql_test_env: Construct env early
cql_test_env: De-static fdpinger variable
cql_test_env: Define all services' variables early
cql_test_env: Keep group0_client pointer