Update asNodeList() on common/Config

[arjav-desai]

While the code to change may not be in repo yet common/config/src/main/java/io/helidon/common/config/Config.java

ConfigValue<List> asNodeList() throws ConfigException;

its coming as part of common-config pr #6448 and pico pr as well https://github.com/helidon-io/helidon/pull/5750/files#diff-557d7016d9aceb8cd7b08e48eeb87fe488ba13da5c79a3acabc6ed52d3196acbR228

There is a review comment on first PR i.e. #6448 (comment)

I think that this would allow you to assign the result into a list of a arbitrary implementation of Config, eg.:
ConfigValue<List> myConfig = commonConfig.asNodeList();
Which breaks type safety (as the result is most likely going to be somebody else's implementation of config)
To make this right, we would have to have the C defined on the Config type, but that would create a lot of problems.
I think this must be changed

[tomas-langer]

To correctly fix this issue, we would have to fully separate API and implementation of Config. This would be a huge backward incompatible change.
I am investigating options to make this a bit less impactful. We may actually end up with this "wrong" method to be able to maintain backward compatibility for our users

[tomas-langer]

I am closing this issue as will not fix.
Although this can create a code that compiles and failes at runtime, you would have to do some custom code to achieve that, which would already require understanding of the problem.
I think we can accept failure in such an edge case, with the benefit of very small impact to our users.