add UI configurable entity_picture to entity options

[Mariusthvdb]

just like we can set an icon in the UI interface, please allow setting an entity_picture.

currently we have to do that in yaml customize, and at least in my config, makes for 90% of that customize...

homeassistant:

  customize_glob:

    scene.*arctische_dageraad:
      entity_picture: /local/hue_scenes/arctische_dageraad.png

    scene.*chinatown:
      entity_picture: /local/hue_scenes/chinatown.png

    scene.*concentreren:
      entity_picture: /local/hue_scenes/concentreren.png

    scene.*_disturbia:
      entity_picture: /local/hue_scenes/disturbia.png

or

homeassistant:

  customize:

    device_tracker.ha_main:
      entity_picture: /local/home-assistant/picture.png

    device_tracker.hvb_macbook_pro:
      entity_picture: /local/home-assistant/picture.png

    device_tracker.plugwise_smile:
      entity_picture: /local/devices/anna.png

would be very nice if we could simple add an entity_picture picker, and set it directly inside the UI.

and yet:

no entity_picture option.

hope you will consider