WebAPI for database integrity added

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".

src/WebApi/Program.cs

@@ -0,0 +1,44 @@
+using Microsoft.EntityFrameworkCore;
+using Microsoft.Net.Http.Headers;
+using WebApi.Data;
+
+var builder = WebApplication.CreateBuilder(args);
+
+// Add services to the container.
+
+builder.Services.AddControllers();
+// Learn more about configuring Swagger/OpenAPI at https://aka.ms/aspnetcore/swashbuckle
+builder.Services.AddEndpointsApiExplorer();
+builder.Services.AddSwaggerGen();
+
+builder.Services.AddDbContext<WebApiContext>(options =>
+{
+	options.UseMySql(builder.Configuration.GetConnectionString("Y4FDB"),
+	Microsoft.EntityFrameworkCore.ServerVersion.Parse("8.0.23-mysql"));
+});
+
+
+var app = builder.Build();
+
+// Configure the HTTP request pipeline.
+if (app.Environment.IsDevelopment())
+{
+	app.UseSwagger();
+	app.UseSwaggerUI();
+}
+
+//ip:port from y4f
+app.UseCors(policy =>
+	policy.WithOrigins("http://localhost:5248", "https://localhost:7138")
+	.AllowAnyMethod()
+	.WithHeaders(HeaderNames.ContentType)
+);
+
+
+app.UseHttpsRedirection();
+
+app.UseAuthorization();
+
+app.MapControllers();
+
+app.Run();