Add script to automate build & running kani

[jaisnan]

1. Adds a one-click command to pull, build and run kani
2. Adds a toml file to store the commit info about the HEAD of kani/features/verify-std
3. Checks for caching to prevent re-pulling, and building already compatible kani binary
4. Modifies CI to re-use this script instead of the previous script
5. Add --kani-args to pass arguments to kani command. -p sets the working directory.
6. Adds a CI job to test the entrypoint workflow itself.
7. Default output-format to terse

Extras

Cleans up some print statements in the run_update_with_checks script.

Call-out

1. This does not allow command configuration, so it essentially all proofs in the library by default, which CAN get expensive. I can very easily add a harness filter to ensure that we can process only relevent harnesses.
2. Need to change documentation to use this command instead of using kani directly as is currently suggested.
3. Need to consider move to python, argument parsing with bash is a bad experience.

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 and MIT licenses.

[celinval]

Thanks Jai

[celinval]

Thanks Jai!