Add cargo xtask clippy (#8722)

This PR sets up a `cargo xtask clippy` command for running `cargo
clippy` with our defined set of options.

The intent is to make this easier to manage as we start enabling more
Clippy rules.

Release Notes:

- N/A

crates/cli/Cargo.toml

@@ -15,6 +15,7 @@ path = "src/main.rs"
 
 [dependencies]
 anyhow.workspace = true
+# TODO: Use workspace version of `clap`.
 clap = { version = "3.1", features = ["derive"] }
 ipc-channel = "0.16"
 serde.workspace = true