Add blob detection example on Python

We have an example of `Bitmap Operation` which is made by @MatthewMcGonagle. We need to expand our Python module and example to cover more code of the library. We cannot ask to do a huge task to implement unit or performance tests initially so a small step as an implementation of existing example is reasonable.
Original blob detection example made in C++ locates at `examples/blob_detection` directory.

Start with the existing C++ example in examples/blob_detection and the current Python module and examples. Compare it with the existing Bitmap Operation example to understand how examples are exposed in Python. Done means the blob detection example is implemented for the Python module without requiring the broader unit or performance test work.

Written by the indexing model from the issue text.