Make a file open snippet

We can prompt the user to open a file of a specific type, any type, or a folder.

Then we need:
- to create a url
- start the security access
- create bookmark data
- stop the security access
- serialize and save the url
- deserialze and open the url on the next access

```
Folder UTType
Security Scoped URL
BookmarkData - follows renames
startSecurity...()
   bookmark
   stopSecurity...()
```