Restructure the solution
* The project has been split into the database integration "src/webapi" and the Blazor wasm project "src/y4f".
WebAPI
* API with CRUD capabilities
* The main task of the "WebAPI" project is to access the database data and make it available to the Blazor-WASM project via an API.
* GET example of the allergy table via the file "TestFetchAllergienData.razor", which can be tested via the browser "/TestFetchAllergienData".
