Prettify filters alignment on searchs

* Adjust the vertical spacing to 6 between filters
* Add an extra HBox so we are able to add a padding of 6, making the filters
  have more space from the window edge
* Remove an extra spacing from print_slave as their the way it is used

Change-Id: Iedc36ba9f50f4b72724c1a2b62b8e43829142028
Remove an unneeded api marked with a FIXME

Change-Id: I19c071d3539d3c6df200c364d9b825b56e972cca