feat(cli): rework uplc subcommands

closes #553

* rename flat to encode
* rename unflat to decode
* alias both to their old names
* both only print to stdout
  use can pipe to file
* split cbor and hex flags
* hex flag works for either cbor or flat
* encode takes --to flag
  [name, named-debruijn, debruijn]
* decode takes --from flag
  [name, named-debruijn, debruijn]

crates/uplc/src/lib.rs

@@ -2,7 +2,7 @@ pub mod ast;
 pub mod builder;
 pub mod builtins;
 mod debruijn;
-mod flat;
+pub mod flat;
 pub mod machine;
 pub mod optimize;
 pub mod parser;