Support for C# 14 Extension Members

[lemonmojo]

Docs: https://learn.microsoft.com/en-us/dotnet/csharp/whats-new/csharp-14#extension-members

This was started in https://github.com/royalapplications/beyondnet/commit/5c8214bc3cdb723dddd8c2ce5a4975792372ca2f. But it's incomplete as the extension members are not yet tied to their extended type so it's currently only possible to call such members through the type that includes the extension (ie. Person_Extensions in the managed sample).

Points of interest:

• https://github.com/royalapplications/beyondnet/blob/main/Generator/Beyond.NET.CodeGenerator/Collectors/MemberCollector.cs#L166
• https://github.com/royalapplications/beyondnet/blob/main/Generator/Beyond.NET.CodeGenerator/Collectors/TypeCollector.cs#L398
• https://github.com/royalapplications/beyondnet/blob/main/Generator/Beyond.NET.CodeGenerator/Syntax/State.cs#L139
• https://github.com/royalapplications/beyondnet/blob/main/Samples/Beyond.NET.Sample.Managed/Source/Person_Extensions.cs#L23
• https://github.com/royalapplications/beyondnet/blob/main/Samples/Beyond.NET.Sample.Swift/Tests/TestClasses/PersonTests.swift#L338