add more nimble example

1. make heart rate sensor example really work
using nRF Toolbox HRM
2. add master device scan example
3. add gatt server example(seems not working)

components/connectivity/Bluetooth_5.0/porting/TencentOS_tiny/src/nimble_port_tencentos_tiny.c

@@ -69,7 +69,5 @@ nimble_port_tencentos_tiny_init(k_task_entry_t host_task_fn)
     if (err != K_ERR_NONE) {
         return;
     }
-
-    tos_knl_start();
 }