Facilitate compilation of plain sierra programs

[Arcticae]

We are using in forge the cairo_lang_sierra::program::Program class and compiling it down to CASM with cairo_lang_sierra_to_casm::compiler::compile.

This binary should be able to compile that artifact as well

Reference:
https://github.com/foundry-rs/starknet-foundry/blob/master/crates/forge-runner/src/sierra_casm_runner.rs#L67