Optimize OpenCV for RISC-V

The main objective of the project is adding implementation of wide universal intrinsics for RISC-V in OpenCV Hardware Acceleration Layer (HAL). RISC-V Vector Extension is the primary option for vectorization in this project. I am very familiar with RISC-V Vector instructions. I believe I have enough time and energy to complete this project. I am looking forward to working with interesting people in OpenCV, and I will try my best to complete the project.