Automatically detect package manager

[scripthunter7]

VSCode has a command to detect the package manager: npm.packageManager.

This setting could be combined with our package manager logic to make the process automatic (in the current solution, user can only set the preferred package manager manually).

References:

• https://github.com/microsoft/vscode/issues/102050
• https://github.com/shivangg/vscode/blob/master/extensions/npm/README.md#settings
• https://code.visualstudio.com/api/extension-guides/command#using-a-custom-when-clause-context

  import { commands } from 'vscode';
  // ...
  await commands.executeCommand<'npm' | 'pnpm' | 'yarn'>('npm.packageManager')

If I understand correctly, this cannot be used directly in the language server, so there are two options:

• pass detected package manager from client to server
• an alternative solution might be to detect the lock file type (VSCode also does this)