Optimization without dependencies in CompilerStack

[cameel]

Fixes #15179.
Depends on #15229.
Replaces/closes #15182.
Includes commits from #15228.

This PR builds on the refactor from #15229, making CompilerStack actually take advantage of the new structure. IRGeneratorOutput can now be parsed into a partial Yul Object that does not contain dependencies and can also be optimized in this form.

What we have here should already be good enough for #15179, but it we wanted to, we could go one step further and extend it to reusing EVM assemblies, avoiding repeating the Yul->EVM transform.

Status

Mostly done in terms of functionality. Needs resolving a few final snags, some cleanup and testing.

• Need a less hacky way to bypass dependency checks in Yul analysis.
• Change in MSize detection inconsistency (can't detect it in dependencies at optimization time but can at assembling time).
• Should I generate IR source only on demand and work primarily with the partial Objects, without serializing and reparsing them?
• More testing.

[cameel]

Just like in case of #15182, closing because we won't be merging it. The actual fix is based on caching optimized IR instead.