Updated PngChunkFlags enum

- Added copyright notice to the header that was previously missing.
- Added `#if NETSTANDARD == false` to hide `[Flags]` attribute for non-.NET Standard frameworks.
   This resolves build failures on Windows ARM64 processors.
- Added justification to SuppressMessage in PngChunkFlags
"The lowercase names are consistent with the naming conventions of PNG chunk types as defined in the PNG specification."

src/Magick.NET/Formats/Png/PngChunkFlags.cs

@@ -1,78 +1,81 @@
-using System;
+// Copyright Dirk Lemstra https://github.com/dlemstra/Magick.NET.
+// Licensed under the Apache License, Version 2.0.
 
-namespace ImageMagick.Formats
+namespace ImageMagick.Formats;
+
+#if NETSTANDARD == false
+    [Flags]
+#endif
+
+/// <summary>
+/// Specifies the chunks to be included or excluded in the PNG image.
+/// This is a flags enumeration, allowing a bitwise combination of its member values.
+/// </summary>
+[System.Diagnostics.CodeAnalysis.SuppressMessage("StyleCop.CSharp.NamingRules", "SA1300:Element should begin with upper-case letter", Justification = "The lowercase names are consistent with the naming conventions of PNG chunk types as defined in the PNG specification.")]
+public enum PngChunkFlags
 {
     /// <summary>
-    /// Specifies the chunks to be included or excluded in the PNG image.
-    /// This is a flags enumeration, allowing a bitwise combination of its member values.
+    /// No chunks specified.
     /// </summary>
-    [Flags]
-    [System.Diagnostics.CodeAnalysis.SuppressMessage("StyleCop.CSharp.NamingRules", "SA1300:Element should begin with upper-case letter", Justification = "<Pending>")]
-    public enum PngChunkFlags
-    {
-        /// <summary>
-        /// No chunks specified.
-        /// </summary>
-        None = 0,
+    None = 0,
 
-        /// <summary>
-        /// Include or exclude all chunks.
-        /// </summary>
-        All = bKGD | cHRM | EXIF | gAMA | iCCP | iTXt | sRGB | tEXt | zCCP | zTXt | date,
+    /// <summary>
+    /// Include or exclude all chunks.
+    /// </summary>
+    All = bKGD | cHRM | EXIF | gAMA | iCCP | iTXt | sRGB | tEXt | zCCP | zTXt | date,
 
-        /// <summary>
-        /// Include or exclude bKGD chunk.
-        /// </summary>
-        bKGD = 1 << 0, // 0000 0001
+    /// <summary>
+    /// Include or exclude bKGD chunk.
+    /// </summary>
+    bKGD = 1 << 0, // 0000 0001
 
-        /// <summary>
-        /// Include or exclude cHRM chunk.
-        /// </summary>
-        cHRM = 1 << 1, // 0000 0010
+    /// <summary>
+    /// Include or exclude cHRM chunk.
+    /// </summary>
+    cHRM = 1 << 1, // 0000 0010
 
-        /// <summary>
-        /// Include or exclude EXIF chunk.
-        /// </summary>
-        EXIF = 1 << 2, // 0000 0100
+    /// <summary>
+    /// Include or exclude EXIF chunk.
+    /// </summary>
+    EXIF = 1 << 2, // 0000 0100
 
-        /// <summary>
-        /// Include or exclude gAMA chunk.
-        /// </summary>
-        gAMA = 1 << 3, // 0000 1000
+    /// <summary>
+    /// Include or exclude gAMA chunk.
+    /// </summary>
+    gAMA = 1 << 3, // 0000 1000
 
-        /// <summary>
-        /// Include or exclude iCCP chunk.
-        /// </summary>
-        iCCP = 1 << 4, // 0001 0000
+    /// <summary>
+    /// Include or exclude iCCP chunk.
+    /// </summary>
+    iCCP = 1 << 4, // 0001 0000
 
-        /// <summary>
-        /// Include or exclude iTXt chunk.
-        /// </summary>
-        iTXt = 1 << 5, // 0010 0000
+    /// <summary>
+    /// Include or exclude iTXt chunk.
+    /// </summary>
+    iTXt = 1 << 5, // 0010 0000
 
-        /// <summary>
-        /// Include or exclude sRGB chunk.
-        /// </summary>
-        sRGB = 1 << 6, // 0100 0000
+    /// <summary>
+    /// Include or exclude sRGB chunk.
+    /// </summary>
+    sRGB = 1 << 6, // 0100 0000
 
-        /// <summary>
-        /// Include or exclude tEXt chunk.
-        /// </summary>
-        tEXt = 1 << 7, // 1000 0000
+    /// <summary>
+    /// Include or exclude tEXt chunk.
+    /// </summary>
+    tEXt = 1 << 7, // 1000 0000
 
-        /// <summary>
-        /// Include or exclude zCCP chunk.
-        /// </summary>
-        zCCP = 1 << 8, // 1 0000 0000
+    /// <summary>
+    /// Include or exclude zCCP chunk.
+    /// </summary>
+    zCCP = 1 << 8, // 1 0000 0000
 
-        /// <summary>
-        /// Include or exclude zTXt chunk.
-        /// </summary>
-        zTXt = 1 << 9, // 10 0000 0000
+    /// <summary>
+    /// Include or exclude zTXt chunk.
+    /// </summary>
+    zTXt = 1 << 9, // 10 0000 0000
 
-        /// <summary>
-        /// Include or exclude date chunk.
-        /// </summary>
-        date = 1 << 10, // 100 0000 0000
-    }
+    /// <summary>
+    /// Include or exclude date chunk.
+    /// </summary>
+    date = 1 << 10, // 100 0000 0000
 }