[WIP][Do Not Review] Add Peer Manager

[MirkoCovizzi]

WIP add Peer Manager.

TODOs:

• Replace app_timer in auth_status_tracker.c and peer_manager_handler.c
• Replace nrf_mtx_t in gatt_cache_manager.c
• Replace crypto in nrf_ble_lesc.c
• Replace FDS in peer_data_storage.c and peer_manager_handler.c
• Replace nrf_atflags_t in peer_id.c and pm_buffer.c

List of changes compared to nrf5 SDK:

• Restructured and moved headers to dedicated folders

• Applied clang-format-15 to each file

• Updated all licenses

• Replaced ret_code_t with uint32_t

• Connection state flags are not present in ble_conn_state so
  use the Kconfig BLE_CONN_STATE_USER_FLAG_COUNT instead.
  Convert the type ble_conn_state_user_flag_id_t to int.

• The configurable values defined in peer_manager.packsc have
  been converted to Kconfig options with a python script, and
  replaced in the code.

• Reformatted all Doxygen to fit NCS style

• Removed nrf5 SDK logging in favor of Zephyr logging

• DOS to unix line endings

• Fix Checkpatch

• Use Zephyr assert in sdk_macros.h

• All includes of headers that do not exist in Bare Metal have
  been removed.

• Changed NRF_ERROR_RESOURCES to NRF_ERROR_DATA_SIZE.
  This is in order to use NRF_ERROR_RESOURCES in stead of
  NRF_ERROR_STORAGE_FULL.

• Changed NRF_ERROR_STORAGE_FULL to NRF_ERROR_RESOURCES.

• Put central logic compilation behind Kconfig flag

• Add some extra build dependencies

• Update GATT Cache Manager by porting nrf_mtx logic

• Update peer_id and pm_buffer to use atomic_t

[github-actions]

You can find the documentation preview for this PR here.