enable C++17

[Yurlungur]

PR Summary

Bump to C++17. It's finally time @mauneyc-LANL

PR Checklist

• [ ] Code is formatted. (You can use the format_spiner make target.)
• [ ] Adds a test for any bugs fixed. Adds tests for new features.
• [ ] If preparing for a new release, update the version in cmake.

[mauneyc-LANL]

As I said in https://github.com/lanl/ports-of-call/pull/39, I'll wait on these to get in so I can make some better use of 17 (apply! (1 + ...)!!