Support `isAI` property on `CodeAction`

[StellaHuang95]

The Typescript team has added Copilot suggestions to various refactors in VS Code. To bring similar functionality to python code, Pylance has enabled the implement inherited abstract classes with Copilot code action through the Github Copilot extension for Python files.

To display the sparkle icon for the code action instead of the regular light bulb icon, the isAI property needs to be set to true on the codeAction.