CLI Changes Sub-PR: New structure and parsing logic (#591)

* Add env feature to clap and cargo update

* Dead Code: WIP CLI changes

* Dead Code: CLI feature parity

Although see clap-rs/clap#5020

* Note about not (yet) using infer_subcommands

See clap-rs/clap#5021

* Use clap/wrap_help

Although see clap-rs/clap#5022

* WIP: Strip out previous CLI argument parser setup

[skip ci]

* WIP: Normalise arguments for caller

[skip ci]

* Don't check for file-ness in the CLI argument parser

* File and directory canonicalisation for the argument parser

* Expose CLI types so they can be used downstream

topiary-cli/Cargo.toml

@@ -26,7 +26,8 @@ path = "src/main.rs"
 [dependencies]
 # For now we just load the tree-sitter language parsers statically.
 # Eventually we will want to dynamically load them, like Helix does.
-clap = { workspace = true, features = ["derive"] }
+# NOTE clap/wrap_help isn't perfect (see clap-rs/clap#5022)
+clap = { workspace = true, features = ["derive", "env", "wrap_help"] }
 env_logger = { workspace = true }
 futures = { workspace = true }
 directories = { workspace = true }