[ Xdebug ] Add Xdebug use case examples

[mho22]

Motivation for the change, related issues

To help developers familiarize themselves with the Xdebug dynamic extension, several use case examples have been implemented.

cc @fellyph

Implementation details

Added Xdebug use cases for :

- PHP.wasm CLI in VSCode
- PHP.wasm Node in VSCode
- Playground CLI in VSCode

- PHP.wasm CLI in PhpStorm
- PHP.wasm Node in PhpStorm
- Playground CLI in PhpStorm

- PHP.wasm CLI in Chrome Devtools
- PHP.wasm Node in Chrome Devtools
- Playground CLI in Chrome Devtools

Testing Instructions (or ideally a Blueprint)

• Clone this repository
• cd examples/xdebug/ide or examples/xdebug/chrome-devtools
• explore the different use cases and follow the steps in the dedicated README.md files