Wrap and document BNPrepareToCopy APIs

What is the feature you'd like to have?
The core API functions BNPrepareToCopyLowLevelILFunction and BNPrepareToCopyLowLevelILBasicBlock are currently completely undocumented, despite being necessary for the official inliner example. Additionally, no wrapper is exposed to Python, so even when you know what they are for, you can't call them without manually using the core API.

Are any alternative solutions acceptable?
If these APIs could be automatically handled when necessary, that would be great. Unfortunately, I'm not entirely clear on their use or necessity, other than the fact that they are used by the inliner.

Additional Information:
This is the description I got on the Slack:

The short of it is that they end up copying the labels for the targets of outcoming edges of blocks.

Unfortunately, I don't quite understand what that means...

Start with examples/workflows/inliner/inliner.cpp at the linked use of BNPrepareToCopyLowLevelILFunction and trace both named core APIs to understand how outgoing-edge labels are copied. Done means documenting both APIs and exposing Python wrappers, with the inliner use case providing the available behavior to verify.