Add expanded harness name to cargo kani arguments

[jaisnan]

Description of changes:

Kani's --harness returns a fuzzy output, which cause issues for the extension when there's multiple harnesses under the same name. With this patch, the extension passes the fully qualified name to kani as an argument, preventing more than one harness from being run.

Changes from PR

1. Adds fully qualified name to the harness command
2. Adds fully qualified name to concrete playback button and command
3. Adds unit tests for the module name
4. Refactors paths invoking the harness name to be more modular, like the cargo kani --test pathway.

Tackles #39

Testing:

• How is this change tested? Manual and Unit tests

• Is this a refactor change? Yes

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.

[feliperodri]

LGTM.

[celinval]

This is a heuristic at this point, which is probably better than what we have.

I do recommend that you read: https://doc.rust-lang.org/book/ch07-01-packages-and-crates.html and https://doc.rust-lang.org/book/ch07-02-defining-modules-to-control-scope-and-privacy.html to understand the rules of how qualified names are built.