Investigate if onEnter formatting works well with clang-format

[sean-mcmanus]

We wanted to do onEnter formatting with clang-format several years ago, but it wasn't working so we just did ";" onType formatting.

We want to make sure that adding new lines is still possible.

[bobbrow]

Closing this issue as lower priority since it's become stale and there are no comments from the community about it in recent history.