Merge .NET runtime startup and exception settings

- Added runtime overrides for path handling and long paths
- Included legacy exception and unhandled policy settings
- Updated supported runtime version to v4.6.2

QuickLook/App.config

@@ -1,6 +1,12 @@
 <?xml version="1.0" encoding="utf-8"?>
 <configuration>
+  <startup>
+    <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.6.2" />
+  </startup>
   <runtime>
+    <AppContextSwitchOverrides value="Switch.System.IO.UseLegacyPathHandling=false;Switch.System.IO.BlockLongPaths=false" />
+    <legacyCorruptedStateExceptionsPolicy enabled="true" />
+    <legacyUnhandledExceptionPolicy enabled="1" />
     <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
       <dependentAssembly>
         <assemblyIdentity name="System.Runtime.CompilerServices.Unsafe" publicKeyToken="b03f5f7f11d50a3a" culture="neutral" />