Add new option to override EntityID when acting as IDP
A possible solution for #1549 (closed)
Overriding Lasso's ProviderID during init of Issuer::SAML makes LemonLDAP emit assertions with a different entityID without having to override it everywhere
As of !61 (merged), this PR now includes publishing the overriden EntityID at /saml/metadata/idp
Edited by Maxime Besson