Sway Test Explorer

The app-dev team recently suggested taking a look at the [Mocha Test Explorer](https://marketplace.visualstudio.com/items?itemName=hbenl.vscode-mocha-test-adapter). It has a side bar showing all of the test functions in the file. You can then run or debug each test using UI elements in the side panel. Would be really cool if we could do something similar.


@mitchmindtree mentioned, "In theory something like this should eventually be possible using a combination of the forc-test crate (currently pretty limited) and a future Sway debugger (heavily WIP, currently blocked)."