suspend the radio before blocking io

[winnieXY]

acl.save() is blocking IO - during this time the nrf52 CPU is halted. If this happens in between a spi transaction with the sx1262 the bus is corrupted and the radio is stuck. the issue does not occur on esp32 as esp32 has a separate flash controller.

This behaviour is correctly detected by the repeater and the _err_flags are set:
_err_flags |= ERR_EVENT_STARTRX_TIMEOUT;
However - no action is taken upon that error yet.

There are two countermeasures - and one general countermeasure:

• use non-blocking io (not trivial to near impossible on nrf52)
• suspend the radio before writing the acls to prevent spi bus corruption
• (restart the transmitter after a error was detected)

The last one is described within a separate PR - see #2347 - in order to have cleaner PRs. This PR is a attempt to mitigate the spi bus corruption by suspending the radio before the blocking operation.