RootCanal: Implement all Role Change configurations

Role change may be requested at connection setup, or
after the connection setup, and rejected based on
specific configuration each time;

Listed below are the tested configurations:
- Peripheral connection at Setup, Accepted
- Peripheral connection at Setup, Rejected
- Peripheral connection, Accepted
- Peripheral connection, Rejected
- Central connection at Setup, Accepted
- Central connection at Setup, Rejected
- Central connection, Accepted
- Central connection, Rejected

What is not properly documented in the core specification, but is
well defined in the LMP test cases; a successful role switch
always generates an HCI Role Change event, at setup or not.

Bug: 274248798
Test: atest --host rootcanal_ll_test
Change-Id: Idf251f4e8234c015fc43863cd3d7f7928a510c2d