Reuse of Pybind

**Is your feature request related to a problem? Please describe.**
I want to make a Python - C++ library that would depend on Open3D.
I need to pass triangle mesh back and forth. For that I would like to reuse pybind files from Open3D.

**Describe the solution you'd like**
Make cmake module that is installed during `make install` such that it can be defined as a dependancy in __CMakelists.txt__ in target library.

**Describe alternatives you've considered**
Open to any suggestions.

**Additional context**