Test "serverReadyAction" feature

[weinand]

Test for #69311:

• anyOS: @isidorn
• anyOS: @roblourens

Complexity: 3

Authors: @weinand

For a description of the feature, please see #69311 (comment).

Verify....

• you can use Intellisense to add the serverReadyAction property (and its properties) to any launch config and hovering over the properties explains what they do.
• it works out of the box for a node.js "express" application both for openExternally and debugWithChrome actions (see https://code.visualstudio.com/docs/nodejs/nodejs-tutorial#_an-express-application for how to create an express app)
• create a simple server application in another language (e.g. C# or Python, etc.) and configure the pattern property to match the trigger message.
• modify the urlFormat to make VS Code use a "https" URI (for a port pattern).

Please note:
There is an inconsistency with the property "uriFromat": Intellisense suggests "uriFormat" but the code actually expects "urlFormat". So you will have to use "urlFormat" until this is fixed (#69344).