Port tests in `explain.rs` to sqllogictests

[alamb]

Is your feature request related to a problem or challenge?

Part of #6195. We are trying to keep the DataFusion code base clean and easy to contribute to and modify. Part of doing so is having a single location for most test coverage so new tests can be added easily and people can follow the existing patterns easily

Describe the solution you'd like

Port the tests in https://github.com/apache/arrow-datafusion/blob/main/datafusion/core/tests/sql/explain.rs to explain.slt in https://github.com/apache/arrow-datafusion/tree/main/datafusion/core/tests/sqllogictests/test_files

For this particular test, I think the best thing to do is to test EXPLAIN VERBOSE on a simple explain plan which will show the different passes

Notes:

1. Instructions for running sqllogitest are here: https://github.com/apache/arrow-datafusion/tree/main/datafusion/core/tests/sqllogictests

Describe alternatives you've considered

No response

Additional context

No response

[alamb]

This is a very small test to port

[my-vegetable-has-exploded]

I'd like to try it.

[alamb]

Thank you @my-vegetable-has-exploded (great github tag btw)

[my-vegetable-has-exploded]

my-vegetable-has-exploded@ae8ff25
Does this commit meet the requirements? Its output is a bit tedious.
@alamb

[alamb]

Does this commit meet the requirements? Its output is a bit tedious.

Yes I think so -- thank you @my-vegetable-has-exploded

I know the output is tedious but the upside is that it is east to update / maintain as sqllogictest style tests

[my-vegetable-has-exploded]

Get it!
Thanks, @alamb