Saml adapter XML configs should be formatted

Description

Right now, SAML adapter configs, when downloaded for mod_auth_mellon are downloaded in a zip containing several XML files with no formatting (whitespace/newlines).

Keycloak should output xml files with more formatting info than a single line with no whitespace.

Discussion

No response

Motivation

Unformatted XML makes debugging harder. (Note that the SAML adapter config also fails to format the certificate and key properly, which breaks mod_auth_mellon, that's a different issue).

I was able to clean my xml files up with xmllint --format but this should be something Keycloak does by itself without needing a third party utility.

Details

I don't know Java internally well enough to know if there's a native ability to do this, sorry. But if there's enough function to be able to generate a .zip file, this has to exist somewhere. Failing that, even adding newlines after every > would be something.