ValidateNFDeploy is the validation function for validating a given NFDeploy An NFDeploy is invalid when - NFDeploy name is empty - Two sites (NFs) with same name are present - NFType is not recognised (Other than AMF/SMF/UPF) - More than one connection is present between two sites - site A is present as connection of site B, but not present in list of sites - site A is present as connection of site B, but site B is not present as connection of site A.