color: input colorspace auto-detection, HDR export tags, LGG/white balance nodes, more LUT formats, waveform parade

- media color primaries/transfer tags now flow from the FFmpeg probe
  through VideoParams into Footage::get_colorspace_to_use(); precedence
  is user override > media tags > project default
- export nclc tags derive from the output colorspace (PQ/HLG/BT.2020,
  P3, sRGB, Rec.601, Rec.709) instead of hardcoded BT.709
- new OCIO Color Grading (Log) node (lift/gamma/gain) and White Balance
  node (kelvin temperature + tint, HDR-safe)
- LUT whitelist extended to 9 OCIO-supported formats
- waveform scope gains an RGB parade mode (GPU and software paths)
- tests updated for the new colorspace precedence

tests/gtest/render_videoparams_test.cpp

@@ -14,6 +14,8 @@ TEST(RenderVideoParams, SaveLoadRoundTrip)
 	params.set_frame_rate(olive::core::Rational(24, 1));
 	params.set_pixel_aspect_ratio(olive::core::Rational(1, 1));
 	params.set_colorspace(QStringLiteral("test"));
+	params.set_color_primaries(9);
+	params.set_color_transfer(16);
 
 	QByteArray xml;
 	QBuffer buffer(&xml);
@@ -39,4 +41,6 @@ TEST(RenderVideoParams, SaveLoadRoundTrip)
 	EXPECT_EQ(loaded.frame_rate(), olive::core::Rational(24, 1));
 	EXPECT_EQ(loaded.pixel_aspect_ratio(), olive::core::Rational(1, 1));
 	EXPECT_EQ(loaded.colorspace(), QStringLiteral("test"));
+	EXPECT_EQ(loaded.color_primaries(), 9);
+	EXPECT_EQ(loaded.color_transfer(), 16);
 }