PF PKI Allow multiple certs to be created with the same CN

[robbel1]

When deploying certificates via SCEP get the following message when common name isn't unique.
"failed to sign CSR" err="Certificate with this Subject already exist:"

We would like to be able to issue multiple certs to client devices via Intune SCEP for Windows and MacOS and Google Workspace for Chromebooks. The CN is set to UPN or user email but if a user signs into a second device no certifcate is issued, as a workaround we have set the CN to be UPN or email + device serial number but this is still an issue as if the device gets wiped or the chromebook user profile is removed no new user or device certs are issued until the old ones are revoked.

[fdurand]

This have to be reworked in the code/db since cn is the unique key.