Add unit test for Radial Zernike filter
Add unit test for Radial Zernike filter

shikhar413/openmc,johnnyliu27/openmc,liangjg/openmc,walshjon/openmc,paulromano/openmc,walshjon/openmc,paulromano/openmc,wbinventor/openmc,johnnyliu27/openmc,paulromano/openmc,amandalund/openmc,walshjon/openmc,mit-crpg/openmc,smharper/openmc,walshjon/openmc,wbinventor/openmc,shikhar413/openmc,smharper/openmc,amandalund/openmc,mit-crpg/openmc,johnnyliu27/openmc,mit-crpg/openmc,smharper/openmc,amandalund/openmc,mit-crpg/openmc,wbinventor/openmc,johnnyliu27/openmc,smharper/openmc,liangjg/openmc,paulromano/openmc,shikhar413/openmc,wbinventor/openmc,liangjg/openmc,liangjg/openmc,amandalund/openmc,shikhar413/openmc