LibraryInfo for easy library base address getting.

[Kiiyya]

Since the requested changes on https://github.com/Tommoa/rs-process-memory/pull/4 would have required me to undo a lot of stuff, I decided to make some new pull requests.

The GetLibraryInfo trait now also returns an iterator, in case someone is interested in listing what modules are loaded at all. Sadly it returns a Vec<LibraryInfo>, not an Iterator directly, because... Box<dyn Iterator<Item = LibraryInfo>> would be too ugly I think? I don't know, I'm still new to rust and have chosen this project to be a bit of my victim for me to learn it :D.