Change Event to be FFI-safe using NonNull

[timrobertsdev]

Addresses #477.

This was a relatively minor change, as seen by the commit. Local tests were run and passed on Windows and Linux (via WSL2).

[phip1611]

Hi @timrobertsdev,
thanks for the PR. I wonder, didn't our new PR template work for you? Or did you just delete it?

I like the change, but this changes the public API as Event is publicly exported, I think. There are currently no constructors yet, and I don't know if or how 3rd part users depend on that type.. so.. should this be part of the changelog? Not sure right now @nicholasbishop @GabrielMajeri @timrobertsdev

[timrobertsdev]

@phip1611 The PR template indeed didn't seem to get filled at the time, but I was running a -dev channel browser, so I'm assuming it was a rendering bug. I see it on new PRs on -stable and will be sure to use it going forward, my apologies. Should I amend the initial post with it?

Event is indeed publicly exported and the change could break existing 3rd party code, so I do believe it should be a part of the changelog.

[nicholasbishop]

I agree that it should be mentioned in the changelog.

[nicholasbishop]

A couple requested changes: updated Handle docstring and changelog entry.

[GabrielMajeri]

@timrobertsdev The PR looks good now! Could you also run cargo fmt to fix the failing CI?

[timrobertsdev]

@timrobertsdev The PR looks good now! Could you also run cargo fmt to fix the failing CI?

All set.

[nicholasbishop]

Merged, thanks for the PR!