Add command to get env interpreter path

[flying-sheep]

• https://code.visualstudio.com/api/extension-guides/command
• https://github.com/microsoft/vscode-python/blob/9ded8032f6a455289113026ed1dca4c5ed81e6e8/src/client/interpreter/interpreterPathCommand.ts

Could then use this in launch.json: "python": "${command:hatch.envInterpreter?[\"hatch-test.py3.14\"]}"