new description
(1) Generalize SkipTicketAcquisitionForLock to handle setting operation priority to low priority as well as high priority. 

(2) Rename Locker::skipAcquireTicket() with a more appropriate name involving setting the priority to kHigh. 

Preserve the existing functionality of both methods, but give them new names and generalize the RAII type for other operation priorities

old description

Currently, operations can opt out of ticket acquisition via Locker::skipAcquireTicket() and SkipTicketAcquisitionForLock

(1) Investigate the difference between the two opt-out methods: is there an impact on specifying when we acquire the GlobalLock the priority versus having a scope guard to skip ticket acquisition?

(2) Ensure all operations that currently opt out continue to opt out

(3) Maintain legacy behavior that tickets who are high priority skip ticket acquisition, regardless of whether the feature is enabled