[GR-48191] Enable lambda reflection queries

[graalvmbot]

Enables reachability metadata JSON files to register reflective queries on lambda classes. A lambda class is defined according to the following parameters:

• A class within which it is declared;
• Optionally, a method within which it is declared;
• A list of interfaces it implements.

Resolving a lambda can therefore yield multiple classes. This PR includes the necessary changes to the parsing code.

JSON format
The following format is used to specify a lambda class in a reachability-metadata.json file:

{
    "type": {
        "lambda": {
            "declaringClass": "fully.qualified.ClassName",
            "declaringMethod": {
                "name": "methodName",
                "parameterTypes": [
                    "fully.qualified.ParameterType"
                ]
            },
            "interfaces": [
                "java.lang.Runnable"
            ]
        }
    }
}

The "declaringMethod" field is optional. When it is missing, lambda classes will be searched within every method declared in the specified class.

Agent behavior
The Native Image agent now supports lambda classes like regular classes and proxies. It never emits the "declaringMethod" field, as it is not possible to recover this information at run-time from a Class object. Trace files now encode types in the same way as ConfigurationTypeDescriptor, which makes them more flexible and easier to parse.

Backwards compatibility
This change will be backported to all GraalVM LTS versions to enable them to read files containing lambda definitions created by GraalVM 25.0 and higher.