lib: Declare codec field in sco_options
scotest: Add option for SCO socket codec
btio: Add option for SCO socket codec
btiotest: Add option for SCO socket codec
debug
core: Fix MediaEndpoint custom property

With several adapters, MediaEndpoint custom property is only created for the
first adapter. When a new connection happens on another adapter
btd_profile_custom_property_exists fails because the custom property doesn't
exist for this last adapter. In case of HFP, ofono fails with error: "Media
Endpoint missing".

This fix allows endpoint_properties_exists to search for the adapter on which
the connection happened.