hfp_ag: update API

hfp: handle AG send EVR message

hfp: report AG EVR status

hfp: enhanced audio recognition, HF ready for audio

hfp: update examples

hfp_ag: release audio connection only if it was opened before audio VR activated, open audio only if connection does not already exist

hfp_ag: add separate function for voice recognition deactivation

hfp: extend HFP_SUBEVENT_VOICE_RECOGNITION_STATUS with status field, rename activated param to state

hfp demoes, use other dongles - to be removed

hfp: report status code

Revert "hfp_ag: fix HFP_SUBEVENT_PLACE_CALL_WITH_NUMBER"

This reverts commit 855ec9017ed84df755439fa4d14237da269a91f5.

hfp_ag: fix HFP_SUBEVENT_PLACE_CALL_WITH_NUMBER

hfp: use acl_handle and sco_handle in events

hfp demos: remove the warning about unhandled HFP meta events

hfP_ag_demo: remove broken error report (handle as part of individual events)

examples: use `btstack_event.h` getters instead of direct array access, use enum to compare status codes

example: add 'delete link key(s)' to a2dp_source, hfp_ag, hsp_ag

add missing default switch cases

docu: copy editing examples titles

hfp_ag_demo, hfp_ag_client_test: avoid out-of-bounds stack read

Use BTSTACK_FILE__ without __ prefix (MISRAC2012-Rule-21.1)

example hfp/hsp: ignore SCO packets if connection handle doesn't match, use HCI_CON_HANDLE_INVALID

example: register for events after setting up the stack, register for hci events after sm_init()

autoconnect if STDIN is not defined

examples: unify local names and append BD_ADDR