feature: Make the scheduler policy actually pluggable

[gbin]

Thanks for taking the time to suggest an improvement.

Problem statement

Today we have single entry point to call the scheduling heuristic from a ron config file. The generic schduler bundled today is ok but for some more advance application users might want to override that manually (or automatically)

Proposed solution

Not sure yet. Maybe in the Ron file itself we could point to a structure. We need to think about how we can pass parameters and existing logs (for more advance use cases like PGO) as a input

Alternatives considered (optional)

Impact / scope (optional)

• Affected crates, platforms, or features:

Additional context (optional)