* Change Android mainloop, add global config and template projects for XR.
* Change gfx/gles device's process flow for XR, working with other PRs, waiting.
* Change gfx/Vulkan device's process flow for XR, working with other PRs, waiting.
* Change render process for XR.
* Develop XR input and events.
* Develop 3D feature of UI widgets and raycast effect for XR.
Co-authored-by: fqamic <fqamic@vip.qq.com>