Added support for GL_NV_shader_noperspective_interpolation on
the Vulkan and Desktop OpenGL backends

Bug: angleproject:4388
Test: angle_end2end_tests --gtest_filter=ShaderInterpTest.NoPerspective/*
Change-Id: I12473830c0ea8b4fffeae9c4a8ec92d979c8e18c
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2107234
Commit-Queue: Mohan Maiya <m.maiya@samsung.com>
Reviewed-by: Geoff Lang <geofflang@chromium.org>