MacOS App build

[nilshenrich]

Currently the whole release folder is uploaded containing just everything. But only the executable ist needed.

Link:

• https://bitrise.io/blog/post/build-and-deploy-a-flutter-desktop-app-for-macos

[nilshenrich]

App folder selected for bundling since 2af2119 but it's not executed on its own.

[nilshenrich]

Create a .dmg file from flutter app: https://retroportalstudio.medium.com/creating-dmg-file-for-flutter-macos-apps-e448ff1cb0f