Refine Cargo / C++ build integration

[prasannavl]

Summary

• Refine cargo build integration, and fix stale build due to updated Rust libs being untracked on C++ dep tree
  • This PR injects the final librs_exports.a into sources as proxy so that it a part of the dep graph whenever rebuilt naturally
  • Workaround to touch defid.cpp is no longer needed.
• Cleans up the build process removing things that's not practically used and adds noise.
• Refactor cargo Makefile
  • Use RUST_TARGET to set CARGO_BUILD_TARGET which is tracked by cargo (https://doc.rust-lang.org/cargo/reference/environment-variables.html)
  • Uses CARGO_TARGET_DIR env instead of having to pass --target-dir in each step.
  • Use --all-targets when not cross compiling to catch more failures early
  • Uses JOBS var to set CARGO_BUILD_JOBS to maintain coherency across jobs
  • Remove further noise by exporting CC related envs
• Fixes incoherent .cargo/config.toml apply.
  • Moves .cargo/config.toml to the root dir so that it works across all tooling since cargo searches up.
  • Remove workaround no longer needed

make.sh

• MAKE_JOBS is now respected throughout the build and carried coherently across C++ and Rust.
• ./make.sh lib is now available that forwards to the Makefile in /lib for easier execution.
  • ./make.sh lib check / lib fmt / lib fmt-check etc are now used through this.
• compiledb now available with ./make.sh for convenience
• rust-analyzer-check for better consistency across build configs
• _get_default_jobs is now used by default during make to ensure that there's a max cap of 80% of the cores on compiles to now use up all cores. 20% offers minimal difference to compile times, but provides for better dev experience without overloading machines.

Misc

• Move protobuf up to v23.3.
• Use osx universal binaries to simplify.
• Adds .vscode/settings.default.json for recommended coherent settings that avoiding excessive recompilation during dev

Further pending Rust Issues

• Enable cargo test for full code graphs that call C++ libs
• [Fixed] Rust-analyzer and cargo build ends up in different configs due to RUSTFLAGS. What's applied in .cargo/config.toml doesn't seem to be applied to rust-analyzer workflow resulting in multiple compilations and invalidating compile caches all the time.
  • Not sure why, since the target dir is picked up as expected, just RUSTFLAGS aren't applied. Can be verified by looking into the fingerprints json files.
  • Related (May be): rust-analyzer.toml rust-lang/rust-analyzer#13529

Implications

• Storage

  • Database reindex required
  • Database reindex optional
  • Database reindex not required
  • None

• Consensus

  • Network upgrade required
  • Includes backward compatible changes
  • Includes consensus workarounds
  • Includes consensus refactors
  • None