hci: trigger read rssi and write link supervision timeout via gap_connection_tasks

gap: gap_enable_link_watchdog() uses automatic flush timeout to disconnect if data cannot be sent

gap: support periodic advertising

hci: track advertisement set for set params, adv data, scan response commands

gap: implement extended advertising api

hci: add list of advertising sets

hci: replace le_advertisements_enabled with le_advertisements_state.LE_ADVERTISEMENT_STATE_ENABLED

hci: replace le_advertisements_active by le_advertisements_state.LE_ADVERTISEMENT_STATE_ACTIVE

hci: convert le_advertisements_todo.LE_ADVERTISEMENT_TASKS_PARAMS_SET intole_advertiseemnts_state.LE_ADVERTISEMENT_STATE_PARAMS_SET

hci: add le_advertisements_state

hci: read le maximum advertising data length

hci: introduce hci_command_supported, store supported hci commands in single field bitmap

hci: use x-macro to generate enum and mapping for relevant supported hci commands

hci: set le scan parameters via hci_run_general_gap_le during init sequence

hci: rename gap_tasks into gap_tasks_classic

att_server: use uint16 for value_indication_handle

l2cap: fixed_channels_supported instead of fixed_channels

l2cap: provide l2ap_run_information_requests

hci: make hci_number_free_acl_slots_for_connection_type public

license: update text

gap: gap_inquiry_set_scan_activity to set Inquiry Scan Activity

hci: fix stack init with SCO over HCI for BCM controller

gap: allow to set Page Timeout with gap_set_page_timeout

hci: fix typo in GAP_TASK_WRITE_PAGE_SCAN_TYPE

hci: query remote features only once