hci/sm: use btstack_packet_handler instead of (*fn)(type,packet,size) for events

gatt_client: don't forward lower layer events to own clients

att_dispatch: don't forward HCI Events to ATT Client. GATT Client register for HCI Events

use little/big_endian_read/store_16/24/32

use for event types

btstack-config.h -> btstack_config.h

hci_cmds -> hci_cmd

fix missing bstack_ for struct data_source and struct timer. utils->btstack_util

prefix data_source_t and timer_source_t with btstack

prefix run_loop_ functions with btstack_

forgot to add files in earlier commit

run_loop.h -> btstack_run_loop.h

prefix debug with btstack_

prefixed all linked list types and functions with btstack_

rename bk_linked_list_t to btstack_linked_list_t

prefix linked_list

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

split sources into core, ble, and classic