Make more service's methods static

[jplatte]

Description

Continuation of #1313.

Checklist:

• I have run ./ci/run_stable_checks.sh
• I have reviewed my own code
• I have added tests – no because I haven't added anything new

[jstarry]

Thanks @jplatte looks like you need to give the &str error type a 'static lifetime to make CI happy. I think it wasn't needed before due to lifetime elision rules with &self

[jplatte]

@jstarry I was wondering why the CI script exited immediately but decided to just rely on my editor integration. It didn't work for stdweb apparently. Would be nice if there was an easier way to run the CI script, one that doesn't require setting the default rustup toolchain to stable.

[jstarry]

Checks have different behavior on different rust versions. I like the consistency of running checks on stable. Maybe we need a warning in the script if you run without stable?

[jplatte]

That still would make it quite annoying to have to change defaults. I was thinking adding +stable to the commands and conditionally running it in CI (assuming you have non-stable CI jobs).

[jstarry]

Good idea! We can move the stable check into a wrapper script that is only used for CI