As part of acquiring the global lock we automatically acquire the RSTL unless an option is provided to skip rstl acquisition. We should change this to (while under feature flag) acquire an intent instead and maintain that intent token until the lock is being released, then we need to release the intent in the correct lock order (following existing code for RSTL should be sufficient).

This will cover the majority of use cases of the RSTL, which acquire the lock as part of other lock acquisitions such as AutoGetDB. We will need to use the lock mode to determine if we need to acquire read or write intent, and may need to pass in additional information to the global lock to specify local write intent where it is necessary.

Lock free reads should still acquire read intent, so clean this up compared to how it was handled in the POC.

This ticket will end up being the majority change for the project

Still needs to take RSTL until all places where RSTL is taken have been made to use intents, then we can do a ticket to batch turn off RSTL