Avatar enhance with group template

[snehmehta]

closes: #1067

Avatar:
  group-template:
    data: ${ensemble.storage.avatars}
    name: ava
    max: 5
    template:
      name: ${ava}
      variant: square
      styles:
        backgroundColor: yellow
        height: 60
        borderColor: grey
        nameTextStyle:
          fontSize: 24
          color: amber
          isItalic: true