Print Kani version

[adpaco-aws]

Description of changes:

Dusting this off since it'd be great to have for next release.

This PR changes Kani so it prints its version and the invocation type/mode as
Kani Rust Verifier <version> (<invocation>) where <invocation> is either standalone or cargo plugin.

Please note that I'm leaving development version information for later in #2617. We can continue the discussion we started in #2571 here.

Resolved issues:

Resolves #2570

Testing:

• How is this change tested? Two new tests.

• Is this a refactor change? No.

Checklist

• Each commit message has a non-empty body, explaining why the change was made
• Methods or procedures are documented
• Regression or unit tests are included, or existing tests cover the modified code
• My PR is restricted to a single feature or bugfix

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

[celinval]

Shouldn't we print the same blob for all sub-commands as well?

[adpaco-aws]

Addressed all comments.

Shouldn't we print the same blob for all sub-commands as well?

To be honest, this wasn't clear to me. Guessing it's because I'd really like assess to be a tool rather than a sub-command...

[celinval]

Thanks