Add function for projecting color to depth

[belkinirena]

Added function in rsutil.h file: rs2_project_color_pixel_to_depth_pixel(...)

Short description of the function:
With the received depth range and the color pixel, the function creates a list of potential depth pixels (a line in the depth image). The function searches along the line the most compatible depth pixel, the depth pixel that it's projected color pixel is the closest to the original pixel.