Espressif BLE: Heart Rate not working

[dhalbert]

Testing on main (after #9325):

Run ble_heart_rate_simpletest on a Metro ESP32-S3. Does not work on 9.0.5 either.

Fixes and diagnoses already done:

1. xTaskNotifyWait(0, 0, (uint32_t *)&error_code, 200); used several times. 200 is ticks. We changed ticks from 1 per 10msecs to 1 per msec in CONFIG_FREERTOS_HZ = 1000 #9134. I changed to use pdMS_TO_TICKS() to make it tick-length independent.
2. xTaskNotifyWait() above may return error_code BLE_HS_EAGAIN, which has to be handled. I added a routine to handle that and called it in various places.
3. In progress: The default characteristic size for a remote characteristic appears to be zero. By comparison, on nordic it's 20. The zero causes a PacketBuffer only big enough for a 2-byte length to be constructed. That then invokes code which never grows the packet buffer. Looking into this to see where the default characteristic size is set up.