Remove try catches choking all exceptions (#5206)

* remove some try catches choking all exceptions

* rename ExceptionExtension to ReportAsWarning, show full stack instead of just message

* dotnet-migrate try catch clean-up

* fix migration test failures

TestAssets/NonRestoredTestProjects/AppThrowingException/App/Program.cs

@@ -0,0 +1,12 @@
+using System;
+
+namespace AppThrowing
+{
+    class MyException : Exception
+    {
+        static void Main(string[] args)
+        {
+            throw new MyException();
+        }
+    }
+}