aioble peripheral may need throttling to avoid random disconnects

Review aioble's characteristic-notification path alongside the reported concept code and its 50 ms delay behavior. Confirm how rapid successive notifications lead to client disconnects on the stated ESP32-C3 and MicroPython setup. Done means providing an agreed rate-limit or warning approach that prevents the reported instability.

I am using AIOBLE (latest version as per December 2022) on ESP32-C3 with Micropython 1.19 (LOLIN D32 board).
My app uses 3 BT LE services (peripheral role),:

• a custom service for requests (with 1 write-only and 1notify-only characteristics)
• a battery_service
• a device_information service

I observed frequent client disconnects to client (I tested with another ESP32 and with NRFConnect app on Android).
The problem seems to happen more frequently when many requests were done in a rapid succession. In such conditions, the peripheral stopped responding, and disconnected the clients after a while (10-20s). Once the clients reconnected, everything worked again.

I was able to solve the problem after one week of testing, by imposing a minimum delay between all characteristics notifications (in my case 50 ms) : now I don't have any disconnects and everything is stable.

Concept code:

            since_last = time.ticks_ms() - __last_notification_ms
            while _MIN_BLUETOOTH_DELAY_MS > since_last > 0 and not force:
                await asyncio.sleep_ms(_MIN_BLUETOOTH_DELAY_MS - since_last)
                # Need to recheck because another transmission may have happened during await period
                since_last = time.ticks_ms() - __last_notification_ms
            data = __get_notification_data()
            __status_characteristic.write(data, True)
            __last_notification_ms = time.ticks_ms()

I guess there is a minimum delay for physical transmission over bluetooth and handling by RTOS and if we push too many notifications in a short period, something goes wrong. I wrote this issue for informing other AIOBLE users and for suggesting defining a rate limit inside the aioble library, or a warning, because this was quite difficult to troubleshoot.