Allow wifi connection to include optional identity

[inodes]

Would like to provide an identity when connecting to 802.1X network which requires authentication using a username.
Could be achieved possibly using wpa_supplicant -

hostname: black-pearl
wifi:
  interfaces:
    wlan0:
      ssid: "MyNetwork"
      scan-ssid: 1
      identity: "username"
      password: "secret_password"