ludus. Change how resource paths are read from the game tree.

This change is needed to make the code cleaner when reading audio source buffers.
Add an internal resource struct that holds resource data (only path for now).
Change internal read resouce method to use new internal resource struct.
Add an interanl method to read audio source buffers paths.
Implement read object audio sources.
Initial implementation of read audio source - does not create the audio source for now.
ludus. Add reading audio buffer paths from game tree to load tree.

Add move constructor and move operator to auto array.
Implement reading audio source buffer paths in load tree.