Summary:
Now that we use the SDK Style csproj files and target VS2019 we can use a custom attribute
(same as in .Net Core 3.1) to get the compiler to output a ModuleInitializer.
ModuleInitializer can be used to resolve AnyCpu dlls at runtime. Should greatly simplify AnyCpu
support.

Changes:

• Checks if the Assembly.GetEntryAssembly() is MSIL
• Change CefSharp.Core.csproj to use LangVersion 9 so we can get the compiler to output
  the ModuleInitializer
• Remove CefSharpPlatformCheck and other CefSharpAnyCpuSupport checks
• CefSharp.Common.targets still has CefSharpAnyCpuSupport references for backwards compatibility with those with it set and Prefer32bit
  The default behaviour for this case is to simply copy the 32bit libs
• Calling CefRuntime.SubscribeAnyCpuAssemblyResolver multiple times now will simply Unsubscribe the previous resolver

How Has This Been Tested?
Further testing required.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Updated documentation

Checklist:

• Tested the code(if applicable)
• Commented my code
• Changed the documentation(if applicable)
• New files have a license disclaimer
• The formatting is consistent with the project (project supports .editorconfig)

Reference:

• How can I determine if a .NET assembly was built for x86 or x64?