Schema: Remove mixed types: road.flags (Parquet compatibility)

[TheRBajaj]

Description

This PR removes the mixed schema types for road.flags property

Before

road.flags could accept multiple types of values that could be put into the same property like array and string values.

After

roads.flags only accepts array property instead of array and string

Reference

https://github.com/OvertureMaps/tf-transportation/issues/57

Testing

Tested using test script

Checklist

1. Add relevant examples.
2. Add relevant counterexamples.
3. Update in-schema documentation using plain English written in complete sentences, if an update is required.
4. Update Docusaurus documentation, if an update is required.
5. Review change with Overture technical writer to ensure any advanced documentation needs will be taken care of, unless the change is trivial and would not affect the documentation.

[vcschapp]

@TheRBajaj need to fix counterexamples.

1. There are many existing counterexamples that have the old-style flags, but where the intention of those counterexamples isn't to find an error in the road.flags property. Can you please find and fix them all to use new-style flags?
2. Please get in the habit of looking for counterexamples to fix when doing schema changes!
3. Could you also add one counterexample that explicitly tests for invalid old-style flags?

[vcschapp]

@TheRBajaj are you using the pull request template?

Looking at this PR's description, it looks like the template was deleted or trimmed-down. If you're doing that, it's preferable not to.

These are the benefits of the PR template:

1. It has a standard format, so it makes it easier to find expected information in expected places.
2. It helps you not forget things.
3. It has a checklist. Explicitly on the checklist, there's an entry for "Add relevant counterexamples", which would help you remember to do that in this case.

[vcschapp]

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[brad-richardson]

It looks like you have some conflicts to resolve first but LGTM!

[vcschapp]

It looks like you have some conflicts to resolve first but LGTM!

I see it also. @TheRBajaj could you resolve the conflict to make this PR mergable?

[vcschapp]

Merging this despite the fact that validation is currently broken. Some cross-PR conflicts caused merging several previous PRs that by themselves were fine to break validation. It will be easier to merge this first, then fix after.