Add test image

Former-commit-id: 2476eadc6520f4a408c1408be176b03c6971e925
Former-commit-id: 041aa8236803ed8dd5602d9abed887baf2ab3806
Former-commit-id: 88a91cce1426f4e944e2b56c450ed9e24327bf5b

tests/ImageProcessorCore.Tests/Processors/ProcessorTestBase.cs

@@ -24,6 +24,7 @@ namespace ImageProcessorCore.Tests
             //"TestImages/Formats/Jpg/gamma_dalai_lama_gray.jpg", // Perf: Enable for local testing only
             "TestImages/Formats/Bmp/Car.bmp",
             //"TestImages/Formats/Png/blur.png", // Perf: Enable for local testing only
+            //"TestImages/Formats/Png/indexed.png", // Perf: Enable for local testing only
             "TestImages/Formats/Png/splash.png",
             "TestImages/Formats/Gif/rings.gif",
             //"TestImages/Formats/Gif/giphy.gif" // Perf: Enable for local testing only