Use using instead of typedef [test]

[SunBlack]

Changes are done by: run-clang-tidy -header-filter='.' -checks='-,modernize-use-using' -fix

[taketwo]

@SergioRAgostinho these are mostly trivial PRs, but they touch a lot of files. It would be nice to merge them in timely fashion to avoid conflicts. For example, I hope to spend a few hours this weekend with smart pointer transition, and will likely to need to touch some of the lines covered by these PRs.

Do you have any concerns about these, something specific that holding us off? Or just lack of time to review?

[SergioRAgostinho]

Do you have any concerns about these, something specific that holding us off? Or just lack of time to review?

Lack of time to review. Like I said, I'm not putting any priority in reviewing these PRs because they are time consuming and not in the goals for this release. That being said, they are fairly trivial in the changes they make, so feel I'm perfectly ok in merging them with just your review.