a2dp: remove redundant functions

a2dp_source, avrcp: clean up log_info

a2dp_source: trigger set config after all capabilities are reported

a2dp_source: accept sbc configuration from remote sink and stop outgoing activities

a2dp_source: add log info

a2dp_source: reset discovery timer while remote is active as initiator

a2dp_source: track if timer is active

a2dp_source: set delay_report capability for remote, if reported

a2dp_source: call get_all_capabilities instead of get_capabilities

a2dp: cleanup logs

a2dp_source: on reconfigure event, set state to A2DP_STREAMING_OPENED

a2dp_source: fix sep discovery for incoming connection

avdtp/a2dp: add finalize stream endpoint function

avdtp: fix compile warnings

a2dp_source, avrcp_controller: fix warnings

a2dp_source: fix forwarding of delay reporting event

a2dp_source: document behaviour for different use cases, outgoing has priority, streamline code

a2dp_source: keep a2dp state as global

a2dp_source: always emit signaling connection established

a2dp_source: extract a2dp_source_discover_stream_endpoints

avdtp_source: remove send_stream_established_for_outgoing_connection

a2dp_source: handle reconfigure, check if initiator

a2dp_source: notify app on error only for the outgoing connection establishment

a2dp_source: check early if stream endpoint is initialised, later call assert

a2dtp: use a2dp helper functions to send events