Initial version of .NET Solution Launcher

Startup project and solution configuration (Debug|x64, Test|x64, ...) in
the status bar, with build and debug tasks that pass both configuration
and platform. Made for DotRush, whose build never passes -p:Platform and
whose status item shows the configuration but not the project.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0169iPWwKHZoBTNN9qwXiwqk

.vscode/launch.json

@@ -0,0 +1,13 @@
+{
+  "version": "0.2.0",
+  "configurations": [
+    {
+      "name": "Run Extension",
+      "type": "extensionHost",
+      "request": "launch",
+      "args": ["--extensionDevelopmentPath=${workspaceFolder}"],
+      "outFiles": ["${workspaceFolder}/out/**/*.js"],
+      "preLaunchTask": "npm: compile"
+    }
+  ]
+}

.vscode/tasks.json

@@ -0,0 +1,11 @@
+{
+  "version": "2.0.0",
+  "tasks": [
+    {
+      "type": "npm",
+      "script": "compile",
+      "problemMatcher": "$tsc",
+      "group": { "kind": "build", "isDefault": true }
+    }
+  ]
+}