Removed a useless dependency on GLOB. In case get_filename_component fails however, GLOB_RECURSE is used to attempt a fix.

Before it could happen that SOURCE_DIR = source/, and a file is added named a.cpp, but it resides in folder source/subfolder1/a.cpp and it would not be found by get_filename_component, and subsequently GLOB would also miss it.

Other solutions:
- Adding separate source directories in CMakeLists input like with include directories
- Explicitly stating the relative path from the source directory in cmakelists.txt (not tested)

Two cases of GLOB_RECURSE still exist. # TODO: added in those places

*) Many connections between UI and rendering are not yet connected back up and quality of life such as camera starting in a natural position is missing. Currently being rendered using additive blending because it makes debugging slightly easier.

Controls should work as expected from arcballcamera except for translation (ctrl + left mouse + drag) which is counterintuitive. Right mouse to rotate and scroll to zoom, middle press and drag to zoom slowly.

NB: Requires full rebuild