Root-Canal: Implement support for SCO connections

- Add the deprecated HCI command Add_SCO_Connection,
  used by the PTS to setup SCO (and not eSCO) connections.
- Implement SCO link parameter negotiation, report
  correct link type in Synchronous Connection Complete events

Tag: #feature
Bug: 209800014
Test: cert/run
Change-Id: Iefbe5b64594bf0b1a55110342733f4e3a8a39ed0