Added project references to establish dependencies between
the API, Application, Domain, and Infrastructure projects.
Updated `DigitalData.EmailProfiler.Tests.csproj` to include
references to all layers for testing purposes. Fixed a BOM
encoding issue in the test project file. Added xUnit usage
directive to ensure proper test framework integration.
Updated Visual Studio version in the solution file to 17.14.36717.8.
Added three new projects: Infrastructure, Domain, and Application,
all targeting .NET 8.0. Enabled implicit global usings and nullable
reference types in the new projects. Updated solution configuration
and nested the new projects under the `src` folder.
Added a `Worker` class as a hosted background service to log
periodic messages. Updated `DigitalData.EmailProfiler.API.csproj`
to include `UserSecretsId` for secure development storage and
added `Microsoft.Extensions.Hosting` package. Replaced the
`Controllers` folder reference with `Properties`. Updated
`Program.cs` to register the `Worker` service, enable API
exploration, and retain Swagger configuration.
