4.x Generated config metadata for an enum on a @Prototype.Configured type does not list the valid values

[tjquinno]

Environment Details

• Helidon Version: 4.x
• Helidon SE or Helidon MP both
• JDK version:
• OS:
• Docker version (if applicable):

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Problem Description

The generated config metadata JSON does not list the allowed values for an enum property.

Steps to reproduce

1. Create a new public enum type (such as GcTimeType in this PR MP Metrics 5.1 support #9032).

2. On a @Prototype.Configured type (MetricsConfigBlueprint in the PR) add a property of that enum type:

    @Option.Configured
    @Option.Default("COUNTER")
    GcTimeType gcTimeType();

3. Build the component.

4. Inspect the generated META-INF/helidon/config-metadata.json file. It describes the enum property but does not list allowed values.

[tomas-langer]

It would be also good to make sure the allowed values are visible in the generated .adoc file with the javadoc.
Javadoc is only available in case the enum is in the same module as the Blueprint.
In case you need to use an enum from another module, you can add @Option.AllowedValues to describe each value.
Another nice to have would be to have a link to javadoc of the enum (esp. if from another module), so the user can see the values and descriptions.