Add iterators for UUID nodes

[InnocentBug]

Description

Add iterator capability for UUID nodes.

Changes

UUID attributes are strictly strings now.

Known Issues

Notes

Let's add some test to ensure iteration over nodes is dfs, and we need to tests this with a graph that contains cycles.

Checklist

• [ x] My name is on the list of contributors (CONTRIBUTORS.md) in the pull request source branch.
• [ x] I have updated the documentation to reflect my changes.
• [ x] My code changes have been verified by automated tests and pass all relevant test scenarios.

[trunk-io]

🚫 This pull request was closed and has been removed from the merge queue (details).

[InnocentBug]

@duboyal please add tests to this as discussed.
Even if the tests don't work, no worries just add them anyways, and I can debug.

[InnocentBug]

we can't merge it yet, since it is untested

[InnocentBug]

I think the tests show green now.

[InnocentBug]

/trunk merge