[GLUTEN-6834][CORE] Remove unused DDL plan that doesn't correspond to Substrait spec

[EpsilonPrime]

What changes were proposed in this pull request?

This is part of a larger effort to unfork Substrait.

How was this patch tested?

Tested utilizing the available unit tests.

[github-actions]

Thanks for opening a pull request!

Could you open an issue for this pull request on Github Issues?

https://github.com/apache/incubator-gluten/issues

Then could you also rename commit message and pull request title in the following format?

[GLUTEN-${ISSUES_ID}][COMPONENT]feat/fix: ${detailed message}

See also:

• Other pull requests

[github-actions]

Run Gluten Clickhouse CI

[github-actions]

#6834

[EpsilonPrime]

It's worth noting that DDL operations are connected differently in Substrait so that this code would need to be updated before it could be used anyway.

[zhztheplayer]

Hi @rui-mo, where did the code come from, do you remember?

[rui-mo]

This was introduced by CH backend with 614543e. cc: @zzcclp

[zhztheplayer]

+1 if the code is unused

[zhztheplayer]

@EpsilonPrime

By the way I still doubt we can unfork Substrait with minimal effort, though it sounds good. Different native accelerators / libraries would have different ways to implement the same logical computation. It's may not be easy to have a single protocol to unify them at physical level.