imp: cairo/scarb structure suggestions

[drspacemn]

Structure:

• Separate out packages from top-level contracts
• Include packages in virtual manifest
• Remove redundant workspace definitions from workspace packages
• Only define shared resources in top-level dependencies
• Explicit tool version via .tool-versions file
• Define all script testing via snforge
• More explicit visibility

Personal Preferences:

• define all modules in lib.cairo instead of breaking out small file imports
• .workspace = true > = { workspace = true }
• define package versions manually for more granular control
• configure all sub modules under tests with #[cfg(test)] except for mod mocks in order to keep mocks segregated from business logic but still buildable via snforge

Recommendations:

• Include mocks for all components and local testing infrastructure for the components via mocks

[Farhad-Shabani]

All the points you mentioned sound great!

Just as for { workspace = true }, I kept it as-is to stay consistent with the other workspaces. Plus, I found it a bit cleaner to catch at a glance.

On the granular versioning side, since we're still early in development, we'll likely bump the version together for a while until things stabilize. But after, your suggestion definitely makes sense. I also got the meta starknet_ibc package back in.

Only remained local component testing. I opened up #79 to tackle it as a separate effort.

Thanks again for the awesome suggestions and the PR! ✨

[justtry1512]

OK. I'M DOINT IT NOW.