More refactoring: move code to split factor base into pieces into separate functions
More refactoring: move code to split factor base into pieces into separate functions

mancoast/cado-nfs,mancoast/cado-nfs,mancoast/cado-nfs,mancoast/cado-nfs,mancoast/cado-nfs,mancoast/cado-nfs,mancoast/cado-nfs