esp_now: fix doxygen groups

tests/posix_semaphore: increase timeout margin

dist/tools: add support for PyOCD programmer/debugger

drivers/at: add function to read raw data bytes from modem

drivers/sx127x: remove irq_disable/irq_restore around spi transfers

gnrc_sixlowpan: amend gnrc_netapi introduction

 gnrc_netif: remove superfluous GNRC_NETIF_FLAGS_MAC_*

boards/nucleo-l496zg: use lpuart1 as stdio interface

net/ble: add generic advertisement data (AD) processing helper

cpu: esp_common added for common modules of ESP SoCs

Co-authored-by: Vincent Dupont <vincent@otakeys.com>

Co-authored-by: Vincent Dupont <vincent@otakeys.com>

 gnrc_ipv6_nib: use correct reverse-translate for ARSM-less NCE

The current implementation uses the assumption that the IPv6 address is
always based on an EUI-64, which it doesn't has to.

icmpv6.h: fix two small typos

test/xtimer_hang: use xtimer_periodic_wakeup

cpu/stm_common: Refactor and cleanup i2c_1

net/gcoap: allow NULL path in gcoap_req_init()

sam0 flashpage_write: correct translation from RIOT pages to CPU pages writing

cpu/stm32l0: make use of CPU_LINE and STM32_FLASHSIZE

cpu/stm32f1: make use of CPU_LINE and STM32_FLASHSIZE

This enum conflicts with macro definitions from ccn-lite pkg.