As a small developer quality of life improvement, I found many individual unit tests that take longer than around a second to complete, and set them to skip when run under `go test -short`.
On my machine, the wall timings for tests (with `go test -count=1 ./...` and optionally `-short` and `-race`) are roughly:
- Long tests, no race detector: about 1m42s
- Short tests, no race detector: about 17s
- Long tests, race detector enabled: about 2m1s
- Short tests, race detector enabled: about 28s
This PR is split into many commits each touching a single package, with commit messages detailing the approximate timing change per package.