Blenderproc

- fix `Light` class to work properly with `bpy.types.Light` in `load_blend`
- fix the stereo matching example add missing parameter to fct. call

- moved to a full python API support (`.yaml` files are still supported)
- blenderproc can now be installed via pip: `pip install blenderproc`
- complete new structure to most of the files
- offer new command line interfaces: `blenderproc run`, `blenderproc debug`, `blenderproc vis` and many more
- optional/flag arguments can now be used in the users python script
- adds feature to render multiple times in one session (see example `advanced/multi_render`)
- added tutorials to get easy start with BlenderProc
- adjusted all examples to explain how the python API would be used there
- restructured the documentation
- fixed a bug with the view layer update, which wasn't done before the scene coverage score was calculated, which caused problems in the 3D-FRONT examples.
- removed a lot of view layer update calls, which makes the whole execution faster, by manually calculation the `matrix_world`.
- vertex colors can now be used with a Principled BSDF shader
- all images are now moved into a seperate `image/` directory
- all functions now use type hints

- switch to blender 2.93, with that textures are now stored on the GPU between different frames increasing the speed drastically
- moved a lot of modules to the python API
- all camera samplers
- all writer classes
- sampler and getters
- surface lighting
- random room constructor
- all outer API functions work now with numpy arrays instead of mathutils classes
- regroup all examples to make them more easily accessible
- refactoring of the LabelIdMapping class
- sampler.Path now has a `return_all` and `random_samples` option
- add support for the new 3D front labels and script to find them more easily in the future
- AMASS now also supports `torch=1.8.1+cu111`, to better support modern GPUs
- refactor download script for haven
- added a flag to not center objects from the ShapeNet dataset
- added a platform independent unzipping function to solve the problems on windows
- add function to return the default_value or the connected node based on the input name of a BSDF shader node of a material
- fix for MacOS, where the blender version was not used in prior installations, leading to the problem that users had to remove blender on their own
- the writer now correctly writes the fov if asked

- fix a bug on mac os, where the blender python path has changed
- fix a bug in the BlenderLoaderModule which caused that the setting of custom properties was not successful

- BlenderProc now can be executed via a python script (experimental, not all modules are supported yet)
- python API extension for the following modules:
- the Entity & Material Manipulation
- the WriterUtility, Hdf5Writer, BopWriterUtility, CocoWriterUtility
- the PostProcessing
- the physic positioning, PoseSampler
- debugging can now be done via the command line, by just typing --debug after a BlenderProc call
- add automatic convex decomposition to speed up physics, object decompositions will be cached
- add a jupyter notebook example for google colab
- add a BasicEmptyInitializer module, which helps creating simple empty objects, these can be used for using a depth of field
- add a depth_of_field option to the CameraInterface (thanks to cuteday)
- add a hide module, so that certain objects can be hidden in a selected range of frames (thanks to Sainan Liu)
- add an option to change the computation type via the config
- blender 2.92 changed depth and distance once again, we use it correctly now and added an explanation
- added a diffuse rendering mode
- added a key frame API
- added a default config, which can be easily changed
- ObjectPoseSampler now can check also against only a limited set of objects
- ObjectReplacer now stops if no objects are left to replace
- SurfaceLighting now reuses the TextureLess material
- preloading in CCTexture now also works perfectly for textures which use an alpha texture
- python packages now are installed by specifying the required packages at the top of each file
- added an example for pasting objects onto random backgrounds
- added a flag to merge BlenderKit objects, while loading, they will be named after the blenderkit file
- reintroduce persistent transformation scaling to improve stability
- improve the clean up at the start of BlenderProc
- fixed a bug in the Front3DLoader, which avoided the correct setting of the custom properties
- fixed a bug with the once_for_all mode for the randomize materials fct.
- add a simple rerun script to show how BlenderProc is used for creating a diverse dataset
- switch to blender 2.92

- rewritten the `BlendLoader`, which is now able to only load objects of a given type, this will break existing config files as the `load_from` parameter has been replaced by `datablocks` and `obj_types`
- the `MaterialManipulator` can now overlay/mix a texture with a selected material
- the `MaterialManipulator` can now mix/add a material with another selected material, ideal for creating surface imperfections on other materials
- the `MaterialManipulator` can now add a layer of dust on materials, which simulates dust flakes on top of the object, there also exists now an example for it
- `amount_of_repetitions` can now be used with providers
- full integration of the blenderkit module, including modules and textures with an example
- `LoaderInterface` now offers an auto shading mode
- the `CCMaterialLoader` uses now a preselected list of probably useful materials by default to avoid non tileable materials
- restructure loaders and move their functionality to the utilities (necessary for the API changes for 2.0.0)