[feat] Support copy content to `<app>/Contents/Library` folder for Mac app

[zhuhaow]

Describe the problem

I can't find a solution for it yet (maybe I missed something).

It is very useful since this is very widely used by Apple to support certain features.

Auto start

Applications can contain a helper application as a full application bundle, stored inside the main application bundle in the Contents/Library/LoginItems directory. ...

Use the SMLoginItemSetEnabled function (available in OS X v10.6.6 and later) to enable a helper application.

Or get privilege permission securely,

Describe the solution you'd like

Add support to copy files or directories to Library just like resources in bundler but only for macOS.

I'm not sure if bundler is used when running tauri dev, if it's not, then we may need to find another way to make the content available in dev.

Alternatives considered

No response

Additional context

No response

[hankbao]

This would definitely be a handy feature. Both LoginItems & LaunchServices depend on bundling within the app in the Contents/Library folder.

[pi-ka-qiu]

Support copy content to /Contents/Plugins folder for Mac app ?