ROX-33540: adds rate limiting (#499)

- RateLimiter component added between HostScanner and Output
- Metrics added to monitor dropped events
- Tests added to confirm rate limiting behavior

Author: Stringy

Cargo.lock

@@ -18,6 +18,7 @@ clap = { version = "4.5.41", features = ["derive", "env"] }
 env_logger = { version = "0.11.5", default-features = false, features = ["humantime"] }
 glob = "0.3.3"
 globset = "0.4.18"
+governor = "0.10.4"
 http-body-util = "0.1.3"
 hyper = { version = "1.6.0", default-features = false }
 hyper-tls = "0.6.0"

Cargo.toml

@@ -12,6 +12,7 @@ clap = { workspace = true }
 env_logger = { workspace = true }
 glob = { workspace = true }
 globset = { workspace = true }
+governor = { workspace = true }
 http-body-util = { workspace = true }
 hyper = { workspace = true }
 hyper-tls = { workspace = true }