Bluetooth 5 Long Range support

ref https://www.nordicsemi.com/eng/Products/Bluetooth-5
ref https://www.novelbits.io/bluetooth-5-speed-maximum-throughput/

Update 1: iOS 13.4 could enable long range feature on compatible device https://www.reddit.com/r/iOSBeta/comments/fcww2x/feature_ios_134_beta_enables_ble_long_range/

Update 2: advertising on Coded PHY https://devzone.nordicsemi.com/f/nordic-q-a/49799/issue-regarding-nrf52840-long-range-mode

Update 3: SDK example is **ble_app_att_mtu_throughput**

Update 4: nRF Connect App on Android support seem to support Long Range already !!

Update : list of mobile device that is known to support Long Range, source
https://devzone.nordicsemi.com/f/nordic-q-a/33060/is-there-any-smartphone-with-supporting-of-bluetooth-5-long-range-feature/221305#221305

```
Apple Iphone XS
Apple Iphone XS MAX
Apple Iphone XR
Apple Iphone 11
Apple Iphone 11 PRO
Apple Iphone 11 PRO MAX

Samsung Galaxy S10
Samsung Galaxy S10E
Samsung Galaxy S10+
Samsung Galaxy Note 10
Samsung Galaxy Note 10 PLUS
Samsung Galaxy Fold

OnePlus 6
OnePlus 7
OnePlus 7 PRO

Google Pixel 4 XL
Google Pixel 4

Huawei P30
Huawei P30 Pro
Huawei Mate 20
Huawei Mate 20 Pro

Edit:

Xiaomi Mi 9
```

Start by reviewing the nRF52 Arduino Bluetooth implementation and the referenced SDK example, ble_app_att_mtu_throughput. Compare the requested Bluetooth 5 Long Range and Coded PHY behavior with the linked Nordic documentation and device notes. Done should mean Long Range support is implemented and verified on compatible hardware, but the issue does not specify files or tests.

Written by the indexing model from the issue text.