Generate Praefect replication correlation IDs when absent

This is a modification of !1833 (merged).

The original MR had a regression where Praefect would reject requests missing a correlation ID. The corresponding commit was reverted, so this MR includes the reverted changes along with fixes.

This updated version will generate a correlation ID when absent. Additionally, it properly injects the correlation ID into the outgoing metadata (also missing from the original MR). The functionality was verified in GDK and a new test was added to demonstrate the correlation ID generation.

Closes #2461 (closed)