Register custom app scheme for opening to specific functions

Opening the web link `reai-ghidra://{{binary}}/{{function}}` should open the locally installed Ghidra app and take the user to the function `{{function}}`.

User must have previously analysed binary in a local project. 

See [here](https://developer.apple.com/documentation/xcode/defining-a-custom-url-scheme-for-your-app) for OS X support.