Enabled java wrappers for bionspired/retina module

* Java wrappers support for nested namespaces and classes
* Logging of wrapping process
* Python3 support
* Path to bioinspired/retina header
OpenCV has 3 types of modules:
- PUBLIC: core, imgproc, etc
- INTERNAL: ts module
- BINDINGS: python, java, ...
IMHO, "opencv_java" should be filtered out by module type.

Also, please take a look on PR #2861.