OutputMatcher should take a Collection rather than a List

[elharo]

com.facebook.presto.sql.planner.assertions.OutputMatcher should take a Collection rather than a List

Order is not important in this class so this is semantically correct, and I encountered a case where it would have been mildly more convenient to pass in a Set instead of a List.

[wonderfulvamsi]

Hi @elharo and @tdcmeehan I'm new to open source, I'm interning at a company that uses Presto.
This looks like a doable good first issue for me.
Can you please assgine me this?

[wonderfulvamsi]

Hi @elharo I just completed my presto local setup and had a look at the code.

OutputMatcher is being used in a method called withOutput in PlanMatchPattern class.
So i made the code changes in those files.

I did the maven build with tests it was successful.
Let me know if you want me to add any new tests or shall i proceed with the PR.

[elharo]

aend a PR. It's how we review.