arduino: fix ancs example build
event: introduce hci_event_packet_get_type
ancs_client: use btstack_packet_handler_t
introduce meta event for ANCS Client events
use for event types
ancs_client: drop ancs_client_event_t
ble: ancs_client_lib -> ancs_client, example: ancs_client -> ancs_client_demo
prefix data_source_t and timer_source_t with btstack
replace le_command_status_t with regular Bluetooth uint8_t error codes, add le_command_status_t enums to error list
fix paths after source reorg
separate platform specific code and ports for a particular setup