refactor: --version in the CLI

[0xaatif]

Came across this in passing.

Problems with the old code:

• We included the hash of the Rust compiler we used??
  • I suspect we wanted the commit hash of the codebase @temaniarpit27 as implementor or @atanmarko as feature requester to confirm.
• Manually scanned std::env::args for --version rather than using clap's built-in facilities for this.
• EVM_ARITHMETIZATION_PKG_VER was ignored, so I've removed it.
• A single-function module, pet peeve of mine.

I've renamed CIRCUIT_VERSION to KERNEL_HASH, because that's what it is.

See also #451 and #424

[atanmarko]

@0xaatif @temaniarpit27 used the manual parsing of the std::env::args because feature request was that --version works in the same way as the --help command - if you put it anywhere in the arguments, it will print the version and exit (for example, that is how the rustc behaves). Now it does not work that way.

cargo run --bin leader -- clean --version
error: unexpected argument '--version' found

In this case maybe we could put subcommand for version (for the leader same level as clean, stdio etc. so that you run leader version not leader --version) - but for the others, not sure we have everywhere subcommand level. What do you think?

[0xaatif]

Thanks Marko,
I now understand why the previous code was written that way.
The correct fix is to use propogate_version, which I've done in ee93ec4.

Your example case now works.