Phase 0 WP-0.1: Create .NET 10 solution structure with all 17 component projects

17 source projects (Commons + Host + 15 components) and 17 xUnit test projects.
SLNX format, net10.0, nullable enabled, warnings as errors. All components
reference Commons; Host references all components. Builds and tests clean.

tests/ScadaLink.DataConnectionLayer.Tests/UnitTest1.cs

@@ -0,0 +1,10 @@
+namespace ScadaLink.DataConnectionLayer.Tests;
+
+public class UnitTest1
+{
+    [Fact]
+    public void Test1()
+    {
+
+    }
+}