gws: add diff for google accounts

[ubiratansoares]

First PR to enable diffs betwen our configuration and Google Workspace state.

The whole feature would be a much bigger PR, so I decided to split it. This PR looks big but it brings a non negletable amount of boilterplate, so hopefully it is not hard to read. I hope the code style is familiar enough compared with other services we also diff and sync.

For now, this PR adds support for diffing google workspace users, supporting creation and deletion operations. Everything is still detached from the app entrypoint, and integration will come after we are able to run live dry-runs in CI (which requires further configuration on Github Actions).

To make it sure we can define and safely test some rules we want to encode as part of the diff logic, I added a fake GWS API similar approach similar to what we use in github.

Towards #2363

[github-actions]

Dry-run check results

[WARN  rust_team::sync] sync-team is running in dry mode, no changes will be applied.
[INFO  rust_team::sync] synchronizing crates-io
[INFO  rust_team::sync] synchronizing github