feat(image): preserve attribute's values in jans-auth config

[iromli]

Up to v1.0.4, janssenproject/persistence-loader entrypoint adds/removes attributes and/or its values to conform to janssenproject/auth-server configuration.

For illustration, the following code ensures missing private_key_jwt is added to tokenEndpointAuthMethodsSupported attribute.

if "private_key_jwt" not in conf["tokenEndpointAuthMethodsSupported"]:
    conf["tokenEndpointAuthMethodsSupported"].append("private_key_jwt")

However, sometime this behavior is unexpected, for example when users only want to use tls_client_auth for tokenEndpointAuthMethodsSupported attribute, the entrypoint will add missing value to the attribute.

Ref: ticket 10942

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Possible solutions:

1. The janssenproject/persistence-loader entrypoint should only adds/removes top-level attributes, not its values.
2. Add flag/env var to skip updating jans-auth configuration automatically (manual updates can use Config API or jans-cli)

[iromli]

After several tests on possible solution no. 1, there are a couple of issues found so far:

• specifying the old format "authorizationRequestCustomAllowedParameters": ["customParam1", "customParam2", "customParam3"] will break the app as the data type is no longer valid/conform to jans-auth
• since v1.0.3, jans-cli requires urn:ietf:params:oauth:grant-type:device_code grant type (specified in grantTypesSupported and/or dynamicGrantTypeDefault attribute) to work properly