vGizmo3D v.3.1 beta

this is a v3.1 beta release, going toward v4.0 (to unify imguizmo_quat version, also it currently v.3.1 WiP)

Currently is all Work In Progress

For this reason:

Is maintained old version v.2.1.3 in virtualGizmo3D folder: the old "axes" example still refers to that
the new v3.1 beta is in vGizmo3D folder: new OpenGL (and next Vulkan) easy_examples already refer to that
easy_examples was tested on Linux and Windows: GLFW, SDL and eventually GLM, must be already installed (in addition to OpenGL or Vulkan SDK, obviously)
CMake (3.27 or later) find_package works also with <PACKAGE_NAME>_ROOT environment variable

Added secondary rotation for (eventual) spot / light / otherModel, in alternative or together
Documentation: commented calls with Doxygen syntax and inline functionality for supported IDE (to complete/end)
Added easy OpenGL cube examples (GLFW/SDL) verbosely commented
Will be added easy Vulkan examples (GLFW/SDL) verbosely commented, currently available here: (vkCube_06 & vkCube_08 integrated with imguizmo_quat examples)
Removed some redundant functions with (int x, int y) args: are maintained only the (T x, T y) versions
Deprecated some useless functions: will be removed on next version
Deprecated also "vGizmo" 2D class, because not more tested and used in favor of vGizmo3D: vGizmo (virtualGizmo) class will be removed on next version
vGizmo3D will be the new/short name (old include name will be maintained for compatibility)

Please report malfunctions.
Thanks