Disallow comparison operators on contracts

[Marenz]

fixes #11700 depends on #12566

[ekpyron]

[rebased this using github's rebase button]

[ekpyron]

This will need forking of the external test repos.

[leonardoalt]

This will need forking of the external test repos.

Bump this

[cameel]

Since this is a bit stale anyway, maybe it would be a good idea to first submit some upstream PRs changing those comparisons? With a bit of luck, we'll be able to merge it without having to switch to forks. Or we'll at least reduce their number.

[Marenz]

I changed it to a draft until our external tests are ready for this. Updated the issue accordingly as well.

[leonardoalt]

any updates?

[Marenz]

The current state here is that the external tests need to be updated; This is open for take over at the moment.

[cameel]

Looks like we don't have resources to pursue this now and the PR itself is not that complicated so I'd vote for closing this now and getting back to this later, when we can actually spend some time on getting upstream projects to adopt the change.

[ekpyron]

Given the amount of external test failures, i.e. the extent of the real-world usage of these comparisons, I'm closing the PR. Actually, I'm even considering closing the issue, but I'll leave it open for the time being.