Upgrade packer

Summary:
This had collected a bit of dust and we will need to extend this a little for flipper-server.

- Update deps.
- Migrate away from deprecated clap2 model to derive (it's much shorter now and less imperative).
- ~~Some COW changes on how the progress bar crate handles strings.~~ (Reverted as this causes havvoc in `fbsource//third-party/rust`.)
- Upgraded to 2021 Edition.

Reviewed By: nikoant

Differential Revision: D35433571

fbshipit-source-id: ae0a91558610ae46069a5fc5162b524cde759454

packer/src/error.rs

@@ -29,7 +29,7 @@ impl fmt::Display for Error {
             ),
             Self::MissingPlatformDefinition(platform) => write!(
                 f,
-                "Platform {} is not defined in the given packlist.",
+                "Platform {:?} is not defined in the given packlist.",
                 platform
             ),
         }