Add check and prove steps to CI

[carrala]

• Check stage: finds and attempts to check all Cryptol properties. It fails if any of the properties fail.
• Prove stage: finds and attempts to prove all Cryptol properties with a time limit. It records all properties that don't complete in the time period in artifact manual_proves.txt; all successful proves are saved in fast_proves.txt. It fails if any of the properties that completed in the time period fail.
• A handful of failing or hanging properties with Cryptol files are updated to pass these checks.

[RyanGlScott]

I haven't taken a close look at this yet, as it seems like there are some CI-related issues to sort out. Feel free to ping me when you'd like a closer review, however.