Implement debug.List

[mohsalsaleem]

Refers #9148
This PR implements debug.List method that uses reflect package to to list exported fields and methods names on structs/pointers and all keys in a map.

[CLAassistant]

All committers have signed the CLA.

[bep]

Thanks, can you push the "sign CLA button" above?

[mohsalsaleem]

I’ve completed the CLA Signing, but for some reason the bot thinks I have not.

[bep]

I’ve completed the CLA Signing, but for some reason the bot thinks I have not.

You have probably a email mismatch between the mail address you used for the commit (as in: your Git user) and the email address registered on GitHub. You can fix this by adding email aliases in your GitHub profile.

[mohsalsaleem]

Thanks for pointing it out, looks like CLA check passes now!

[mohsalsaleem]

In case I need to add tests, please let me know. I looked around and could not find anything specific to add tests to apart from the init.go file, which I'm unclear on how to structure the example.

[bep]

In case I need to add tests, please let me know.

We need some basic tests. Just create a debug_test.go file and put a basic TestList test with a simple test structs and a map. The init test you can ignore.

[mohsalsaleem]

@bep I just added some basic tests, please have a look! Thanks.

[mohsalsaleem]

I just noticed that the functions also returns fields that are not exported, let me fix that.

[mohsalsaleem]

Fixed the issue, please review.
Thanks.

[bep]

Thanks for this. I need to think a little before pulling this into the main branch. I have tested this a little, and while it does work great on technical level, I fear it may expose too much (deprecated and internal methods (not meant to be used in the templates, e.g. MarshalJSON) which I think may be more confusing than useful. I need to think about a way to filter out those.