Add an FFI to the WARP integration

[emesare]

Right now there is no way to programmatically interact with the WARP integration without pulling in the warp plugin as a rust dependency. We need to provide an FFI for C++ and Python to enable users to add their own matching and UI elements.

The FFI is straightforward because of how the WARP integration was written we shouldn't need to provide any handle and instead pass around the view in place of a "warp handle".

Some notable use cases for such an API:

• C++ frontend UI (see Add a real UI to WARP #6337)
• Sidekick integration
• Custom WARP providers?
• Custom filtering and matching
• Collaboration integration (Maybe as a WARP provider?)