Add a launch configuration to debug currently opened test

[maorleger]

Looking at the variable reference, we may be able to do something like:

   {
      "id": "filename",
      "type": "promptString",
      "description": "(Optional) Enter a part of the test file name (e.g. 'foo' will run 'foo.spec.ts', 'notfoo.spec.ts', 'test.foo.spec.ts', etc.)",
      "default": "${fileBasename}"
    }

Which will use the currently opened file as the default. Looking at the predefined variables There are ways to be smarter about it:

1. ${relativeFile} will contain the following: <workspaceFolder>/sdk/<serviceDirectory>/<packageDirectory>/test/public/node/myTest.spec.ts (for example, if we have that file open)
2. There are command extensions that can be used to split and manipulate that string

We can write a launch config that takes no parameters and smartly splits out the relative path and the filename and passes those in. I suggest we do that separately and I'll create an issue to look into it 👍 It's a great idea IMO