refactor nfs add edit views code

modify EditNFSExportView to handle both add and edit nfs export functionality
 refactor nfs add edit views code

modify EditNFSExportView to handle both add and edit nfs export functionality
refactor nfs add edit views code

modify EditNFSExportView to handle both add and edit nfs export functionality
Merge pull request #446 from kamal-gade/issue#445_refactor_add_edit_nfs_view

refactor nfs add edit views code