Make it also possible (and configurable) to use ePPN for the identifier instead of SHO+uid

[remold]

For eduTEAMS we would like to only use ePPN-attribute and remove the requirement for SHO+uid. Changes to be made:

• change the requiredAttribute function
• change the creation of the internal identifier
• change LDAP provisioning (for searches made bij API)
• Add configuration option to indicate the use of ePPN

[relaxnow]

Fixed in 4.4

[remold]

@relaxnow Can you explain how to change the required attributes from SHO+uid to ePPN?

There used to be a config option 'openConextIdentifierType', but this looks to be changed.

Thanks

[relaxnow]

@remold Requested / Required attributes are now taken from attribute definition file: https://github.com/OpenConext/OpenConext-engineblock/blob/master/application/configs/application.ini#L64