Manuel Stoeckl authored Jan 30, 2022 and David Edmundson committed Mar 03, 2022

This commit expands the QImage-to-GL formatTable to include entries
for RGBX64, RGBA64_Premultiplied, and Grayscale16 image formats.
Uploading 16-bit-per-channel formats is supported by OpenGL and, with
the GL_EXT_texture_norm16 extension, GLES.