Test "runtimeVersion" feature

[weinand]

Test for #25386:

Complexity: 2

• Windows - @ramya-rao-a
• OS X - @aeschli
• Linux - @roblourens

If you are using "nvm" to manage your node.js versions it is now possible to specify a "runtimeVersion" attribute in a launch configuration for selecting a specific version of node.js.

Setup:

• Make sure to use "nvm" on macOS, linux, and "nvm-windows" on Windows.
• make sure to have those node.js versions installed that you want to use with the "runtimeVersion" attribute. E.g. run "nvm install 7.10.1" from the integrated terminal.

Verify that the specified version of node.js is correctly used for the launch session.

Here is an example launch config:

{
	"type": "node",
	"request": "launch",
	"name": "Launch test",
	"runtimeVersion": "7.10.1",
	"program": "${workspaceFolder}/test.js"
}