Breaking changes in Magick.NET 15.0.0

[dlemstra]

This issue describes the planned breaking changes for Magick.NET 15.0.0:

• Move Clone overloads that takes an IMagickGeometry to a new method called CloneArea.
• Reorder names alphabetically in MagickFormat.
• No longer return null when the native call of MagickImage.IPerceptualHash returns zero but throw an exception instead.
• Rename AlphaOption to AlphaAction and OrientationType to Orientation so both Magick.NET and magick-wasm use the same names.
• Change where TQuantumType : struct, IConvertible to where TQuantumType : unmanaged.

Development notes:

• Remove pragma warning disable CS8500