FrameCapture: Capture Texture Environment in MEC. Persist the state of glTexEnv in mid-execution capture for OpenGL ES 1.X contexts. Implement equality operators overload for the TextureEnvironmentParameters struct. Test: angle_end2end_tests --gtest_filter="TextureEnvTest.*" Bug: angleproject:7652 Change-Id: I131eec5c838c9e434e135bd3c6b050fca44c3231 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/3892015 Reviewed-by: Cody Northrop <cnorthrop@google.com> Commit-Queue: Lubosz Sarnecki <lubosz.sarnecki@collabora.com> Reviewed-by: Jamie Madill <jmadill@chromium.org>