message: FormField: handle border radius for IconButton
diff: height: 44px;
  }
  +.FormField__after .IconButton {
  + border-radius: 8px;
  +}
  +
  .FormField__after .Icon--16,
  .FormField__after .Icon--16.Icon--w-8 {
  padding: 14px;
  border: 1px solid var(--field_border);
  background: var(--field_background);
  content: '';
  - border-radius: 10px;
  box-sizing: border-box;
  z-index: 1;
  transform-origin: left top;
  /**
  * iOS
  */
  -.FormField--ios {
  +.FormField--ios,
  +.FormField--ios .FormField__after .IconButton {
  border-radius: 10px;
  }
  /**
  * VKCOM
  */
  -.FormField--vkcom {
  +.FormField--vkcom,
  +.FormField--vkcom .FormField__after .IconButton {
  border-radius: 6px;
  }
  