ci: Enforce that integer type suffix be separated by an underscore.

[daniel-wong-dfinity-org]

This is based on a new tool introduced in #9418. This should not be merged into master until all currently non-compliant code is fixed. That is being done in a bunch of per-team PRs.

In order for this to actually enforce, Claude is telling me that we need to "Add add-integer-type-suffix-separator-status as a required status check". This is something that IDX will need to due, because they have the necessary authority for such things.

[basvandijk]

As also mentioned in the PR that introduces the tool, why not simply do this via clippy.

We can additionally extend the autofix job with a cargo clippy --fix step.

[daniel-wong-dfinity-org]

I am withdrawing this in favor of #9452.

[daniel-wong-dfinity-org]

I hate autofix. I'm pretty sure most people do not expect others (esp not robots) to be adding commits to their PRs. It unexpectedly breaks future git push commands out of nowhere. Such brokenness can be worked around without tremendous effort, but I shouldn't have to do that. It is literally dumping road blocks in my way. Instead, ideally, there should be a one-click fix so that I can see what changes should be made before they get committed (and pushed to GitHub). That way, I know what is going on with code that will have my name on it.