Fix RX_EN handling during RX power saving

[Dom4n]

This PR adds fix for rx enable pin, previously it was not enabled.

Additionally I'm curious if in high interference sites this firmware worked much better for some unknown reason anyway. So I have added cli commands:
get radio.rxps.rfrx_disabled - check if rx_en pin is enabled or disabled
set radio.rxps.rfrx_disabled on/off - enable and disable rx_en pin.

Default state is "rx_en pin always enabled" - even after restart, these commands are not persisted in memory across restarts. So for testing purposes you can enable repeater auto-restart and enable this commad to see if there is any difference, if the repeater becomes unavailable because it lost it's hearing after restart it will be good again.

Minimal fix for rx_en pin if this whole sheningas with new commands are not welcome:

file CustomSX1262.h

  int16_t startReceiveDutyCycle(uint32_t rxPeriod, uint32_t sleepPeriod,
                                RadioLibIrqFlags_t irqFlags,
                                RadioLibIrqFlags_t irqMask) {
    int16_t state =
        SX1262::startReceiveDutyCycle(rxPeriod, sleepPeriod, irqFlags, irqMask);

    if (state == RADIOLIB_ERR_NONE) {
      this->mod->setRfSwitchState(Module::MODE_RX);
    }

    return state;
  }

[IoTThinks]

set radio.rxps.rfrx_disabled on => Before fix
set radio.rxps.rfrx_disabled off => Fix
get radio.rxps.rfrx_disabled

[IoTThinks]

I have merged it.
Thanks alot for the PR.

Just put a note so we can track the changes.
This PR may be required for other LoRa chip (besides SX1262)

For now, RXEN is available for sx126x only.