venus: massive feedback related refactors
What does this MR do and why?
venus: massive feedback related refactors
Summary:
- 1st commit is a massive renaming. No behavior change. See commit message for details.
- the other commits refactored the generic feedback setup stuff.
- reworked sfb cmd alloc/free helpers as well as sfb setup bits
This is a follow up of !27649 (merged) and is to prepare for:
- later qfb related refactors and optimizations
- further optimizations to reduce lock contention
- make all things feedback related lazily initialized