Missing build_index option in Python HAL bindings

[richbai90]

In the documentation there is a property of the RawFileConfig class called build_index. When working with large recordings, the index build process can be both time consuming and memory intensive. In my case, the index building was causing out of memory crashes. I attempted to disable the indexing by setting build_index to False before initiating a device but the property does not exist in the Python binding of that C++ class. I've created PR #164 to address this.