SwigBinding: Extend the binding of `camera` and add initial binding for other modules

[cbentejac]

Description

This PR extends the SWIG binding for the camera module by covering all the classes that are related to intrinsics and distortion/undistortion models. The inheritance relationships are preserved and binded as well. Unit tests in Python for a wide range of the usable methods (functions that do not use Eigen objects or any other unbinded objects) are added.

Initial bindings for the geometry and stl modules are introduced. These bindings are not exhaustive yet and do not allow a correct interaction through the Python interface, so there is no corresponding unit test for now.

Additionally, the following minor modifications are done:

• The FlatSet.hpp file is removed from the stl module, as it was not used anywhere anymore;
• The get_ud_pixel and get_d_pixel functions from the IntrinsicsBase class (and its children) are renamed to getDistortedPixel and getUndistortedPixel to respect the camelCase;
• The Doxygen documentation for several functions in the intrinsics-related classes is harmonized and improved.*

Relates to https://github.com/alicevision/QtAliceVision/pull/68.

Features list

• [x] Extend the binding for the camera module
• [x] Add initial binding for the geometry and stl modules
• [x] Improve the test coverage for the camera module