case-correct web.config and app.config locations when reporting

[brettfo]

From a manual scan of the telemetry I found that a .csproj might contain <None include="App.config" /> but on disk the file is named app.config (note the differing case.) Since most projects with those files are built on Windows but dependabot runs in a Linux container, we do a case-correction pass on those paths because the intent is obvious.