[Phone] Added IVI Phone support

This extension implements the phone interfaces for IVI using phoned.
It replaces the existing wrt-plugins-ivi-hfp used by Modello home screen.

It implements the following api:

- selectRemoteDevice()
- unselectRemoteDevice()
- getSelectedRemoteDevice()
- invokeCall()
- answerCall()
- hangupCall()
- activeCall()
- muteCall()
- getContacts()
- getCallHistory()
- addRemoteDeviceSelectedListener()
- removeRemoteDeviceSelectedListener()
- addCallChangedListener()
- removeCallChangedListener()
- addCallHistoryEntryAddedListener()
- removeCallHistoryEntryAddedListener()
- addCallHistoryChangedListener()
- removeCallHistoryChangedListener()
- addContactsChangedListener()
- removeContactsChangedListener()

Signed-off-by: Jimmy Huang <jimmy.huang@intel.com>
nit comment: 4-space or align with `<<`, I'd prefer
```
std::cerr << "Failed to subscribe for '" << signal_name << "': "
          << listener_id << "\n";
```