Implement BT 5.0 API's

Implement BT 5.0 API's

This patch adds public API's which check whether
LE 2M PHY and LE CODED features are supported
by the adapter or not. These features are introduced
in BT 5.0 Core specification and thus would be
supported by devices enabled with BT 5.0 controller
or above.

This patch also defines new LE BT 5.0 feature defined as following
"tizen.org/feature/network.bluetooth.le.5_0"

Change-Id: I814bd512827bbb500a71e1052a6813f7c92b6bcf
Signed-off-by: Anupam Roy <anupam.r@samsung.com>