[bt][host] Outgoing Connections

* Add support for outgoing connections to BrEdrConnectionManager
* The Host Fidl server will now attempt to initiate a BrEdr connection
when asked to connect to a classic device
* Add outgoing connection unit tests for BrEdrConnectionManager
* TestController - Log opcode when unexpected command is received

Test: bt-host-unittests (GAP_BrEdrConnectionManagerTest.Connect*)
  You can also manually initiate an outgoing connection using bt-cli:

  $ bt-cli
  > connect <device-id>

BT-263 #done

Change-Id: If4e31625a31b7d20031ea09a8f4854806ef66bf4