Add a new entry for running Vim in nodeless environment and load platform-specific modules based on the target.
This PR includes changes to:
- fs. In node, it's node's native fs; in nodeless, it uses vscode.workspace.fs.
- historyFile. In node, it stores the history in file system; in nodeless, it stores in memory.
- logger. In node, it uses winson; in nodeless, it uses browser console.
- lastly, it relies on Webpack to tree shake unwanted code paths (for example, remove nvim related code paths from the bundle in nodeless environment).