Upgrade to .NET 6 and C# 10

[RehanSaeed]

• Fixes .NET 6 Improvements MegaThread #973

All Solution Templates

• Switch to net6.0 target framework.
• Update to .NET 6 NuGet packages.
• Use ArgumentNullException.ThrowIfNull(...).
• Use record class over record.
• Bump actions/checkout to 2.4.0.

API

• Add ProblemDetailsOperationFilter for API template to use.
• Use strongly typed HTTP headers properties instead of headers dictionary.
• Use GetRequiredSection instead of GetSection.
• Make options class properties [Required].
• Remove dotnetRunMessages from launchSettings.json as its no longer required.
• Add hotReloadProfile to launchSettings.json.
• Simplify resolving ApplicationOptions from DI in integration tests.
• Bump Boxed.AspNetCore from 7.0.0 to 8.0.0.
• Bump Boxed.AspNetCore.Swagger from 9.1.0 to 10.0.0.
• Bump Boxed.Mapping from 5.3.0 to 6.0.0.
• Bump Microsoft.ApplicationInsights.AspNetCore from 2.18.0 to 2.19.0.
• Bump Serilog.Enrichers.Span from 1.4.0 to 2.0.0.
• Bump Serilog.Exceptions from 7.1.0 to 8.0.0.
• Bump Microsoft.VisualStudio.Threading.Analyzers from 17.0.63 to 17.0.64.
• Disable Swagger UI in production mode.
• Configure HostOptions.ShutdownTimeout to 3 mins.
• Bump Docker images from 5.0 to 6.0.

GraphQL

• Use GetRequiredSection instead of GetSection.
• Make options class properties [Required].
• Remove dotnetRunMessages from launchSettings.json as its no longer required.
• Add hotReloadProfile to launchSettings.json.
• Simplify resolving ApplicationOptions from DI in integration tests.
• HumanObject.DateOfBirth now uses DateOnly instead of DateTime.
• Removed custom scalar System.DateTime mapped to Date.
• Bump Boxed.AspNetCore from 7.0.0 to 8.0.0.
• Bump Boxed.Mapping from 5.3.0 to 6.0.0.
• Bump HotChocolate.* from 12.0.1 to 12.1.0.
• Bump Microsoft.ApplicationInsights.AspNetCore from 2.18.0 to 2.19.0.
• Bump Serilog.Enrichers.Span from 1.4.0 to 2.0.0.
• Bump Serilog.Exceptions from 7.1.0 to 8.0.0.
• Bump Microsoft.VisualStudio.Threading.Analyzers from 17.0.63 to 17.0.64.
• Configure HostOptions.ShutdownTimeout to 3 mins.
• Bump Docker images from 5.0 to 6.0.

NuGet

• Default to net6.0 target framework.
• Add embedded README.md to NuGet packages (https://docs.microsoft.com/en-us/nuget/reference/msbuild-targets#packagereadmefile).
• Add AnalysisMode option.
• Add ImplicitUsings option.
• Update .editorconfig file.
• Bump Microsoft.SourceLink.* from 1.0.0 to 1.1.1.
• Bump Microsoft.VisualStudio.Threading.Analyzers from 17.0.63 to 17.0.64.
• Switch AppVeyor to use VS 2022 image.

Orleans

• Bump Microsoft.ApplicationInsights.AspNetCore from 2.18.0 to 2.19.0.
• Bump Microsoft.Orleans.* from 3.5.0 to 3.5.1.
• Bump OrleansDashboard from 3.5.2 to 3.6.1.
• Bump Serilog.Enrichers.Span from 1.4.0 to 2.0.0.
• Bump Serilog.Exceptions from 7.1.0 to 8.0.0.
• Bump Docker images from 5.0 to 6.0.

Item

• Update .editorconfig item template.