RootCanal: Implement support for enhanced synchronous link commands

- Implement ENHANCED_SETUP_SYNCHRONOUS_CONNECTION and
  ENHANCED_ACCEPT_SYNCHRONOUS_CONNECTION

- Homogenize the definitions of the synchronous link commands
  in the HCI PDL source specification

Bug: 245578454
Test: None
Ignore-AOSP-First: Cherry-picked from AOSP
Merged-In: I8aade082b4dcf9ad42965c598bb4bfb0ce24e62b
Change-Id: I8aade082b4dcf9ad42965c598bb4bfb0ce24e62b