- Added accountSubscribe, programSubscribe, slotSubscribe and rootSubscribe to rust RpcClient
- Removed duplication on cleanup threads
- Moved RPCVote from rpc/ to client/rpc_response
* Move test-validator to own module to reduce core dependencies
* Fix a few TestValidator paths
* Use solana_test_validator crate for solana_test_validator bin
* Move client int tests to separate crate
Co-authored-by: Tyera Eulberg <tyera@solana.com>