Add a description for the"OIDC ISSUER" configuration of the "LDAP User Import" Application

[mouhb]

On the administration page of the "LDAP User Import" Application the configuration "OIDC ISSUER" do not have a description, see screenshot.
What may be interesting is to explain how "OIDC Issuer" value could be retrieved from the OIDC configuration. Some examples would also be welcome.

The description is also missing on the store documentation.

[trrenty]

Fixed by upgrading the ldap user import app. 17e83fa

[ane-gabriela]

"The URI of the OIDC Issuer. All the users imported using LDAP User Import will be associated to this issuer." was added as description however there are no examples.

@trrenty @snazare I didn't find any information on this on the store https://store.xwiki.com/xwiki/bin/view/Extension/ActiveDirectoryApplication#HConfiguringtheUserImport and the documentation looks pretty outdated. I think it would be very helpful to add as much info as possible on the store for the users, and update the images and missing fields, also with examples to make things clearer on how they work.