Move test-validator to own module to reduce core dependencies (#20658)

* 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>

core/src/lib.rs

@@ -50,7 +50,6 @@ pub mod sigverify_shreds;
 pub mod sigverify_stage;
 pub mod snapshot_packager_service;
 pub mod system_monitor_service;
-pub mod test_validator;
 pub mod tower_storage;
 pub mod tpu;
 pub mod tree_diff;