Possible null reference return.

Single-line comment should be preceded by blank line (https://github.com/DotNetAnalyzers/StyleCopAnalyzers/blob/master/documentation/SA1515.md)

Rename type name IIntegrationEventHandler so that it does not end in 'EventHandler' (https://learn.microsoft.com/dotnet/fundamentals/code-analysis/quality-rules/ca1711)

Rename namespace BuildingBlocks.Abstractions.Web.Module so that it no longer conflicts with the reserved language keyword 'Module'. Using a reserved keyword as the name of a namespace makes it harder for consumers in other languages to use the namespace. (https://learn.microsoft.com/dotnet/fundamentals/code-analysis/quality-rules/ca1716)

Rename type name IDomainEventHandler so that it does not end in 'EventHandler' (https://learn.microsoft.com/dotnet/fundamentals/code-analysis/quality-rules/ca1711)

Rename type name IEventHandler so that it does not end in 'EventHandler' (https://learn.microsoft.com/dotnet/fundamentals/code-analysis/quality-rules/ca1711)

Rename type name IDomainNotificationEventHandler so that it does not end in 'EventHandler' (https://learn.microsoft.com/dotnet/fundamentals/code-analysis/quality-rules/ca1711)

Rename virtual/interface member IRequestStorage.Set<T>(string, T) so that it no longer conflicts with the reserved language keyword 'Set'. Using a reserved keyword as the name of a virtual/interface member makes it harder for consumers in other languages to override/implement the member. (https://learn.microsoft.com/dotnet/fundamentals/code-analysis/quality-rules/ca1716)

Rename virtual/interface member IRequestStorage.Get<T>(string) so that it no longer conflicts with the reserved language keyword 'Get'. Using a reserved keyword as the name of a virtual/interface member makes it harder for consumers in other languages to override/implement the member. (https://learn.microsoft.com/dotnet/fundamentals/code-analysis/quality-rules/ca1716)