Rubberduck: New project format broke XML compilation.

[comintern]

Switching over to the new project format has apparently broken the build process, because the XML file changes are not triggering triggering rebuilds of the *.Designer.cs files. Any XML files that were changed after the switch to the new project format and subsequently pulling into next have created a situation where the XML and associated designer are out of sync (see this comment on #4488).

This was first "discovered" by @IvenBach when his local build broke due to XAML changes, and I later replicated it when _my_ local build broke after making changes to the .resx files in #4483. That PR includes what is intended to be a fix for Rubberduck.Resources.csproj, but any other project that includes any compilable XML is going to require a similar fix.

[bclothier]

We should consider whether we should use this SDK to generally fix the issue before re-inventing the wheel.