feature/adminui class required label

Example, how the changed tempate could be used to style label (I did not included it):

.x-label-required span[role=separator]::before {
    content: '*';
    color: #D0021B;
}

This would add a red asterisk for required field's labels.

IMO, this is a bit better way than abusing Ext.form.field.Base.override.