Allow pausing of cache replay for a specific proof

[unp1]

Please describe your proposal in a ONE sentence

One sentence describing your idea

Allow to pause proof cache replay for a single proof (without needing to switch it off globally)

Underlying problem

A clear and concise description of what the problem is. Ex. I'm always frustrated when [...]

Sometimes (e.g., teaching) one wants to perform the same proof using different alternatives (inlining, contract, manual steps etc.) or simple debugging. In that case proof cache replay means it too well :-)

Usage Scenario

Who (user scenario) would benefit from implementing the idea?
Describe a short use case scenario in which the suggested idea is featured.
Describe the solution you'd like: A clear and concise description of what you want to happen.

I would like to be able to (for example) right-click on the proof caching information in the status line and to pause the caching for the moment and later to resume it.

Alternatives

A clear and concise description of any alternative solutions or features you've considered.
Why is the suggestion the best alternative?

The alternative would be to switch the feature off globally, which is more cumbersome for the few times one wants to switch it off, as in general one really wants caching.

Estimated effort

If you can: Estimate the effort that has to be invested to implement the feature request.
Is there still discussion needed? Or is it purely implementation? Expertises needed?

Additional context

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[WolframPfeifer]

Closed by #3305.