tidy: Fix clang-tidy issues on files changed in this PR

The checks used are roughly the same as the ones proposed in the
clang-tidy PR (except perhaps that I used modernize-* instead of listing
them individually,though I don't think this caused any readability
detriments).

In ModrinthModel.cpp and FlameModModel.cpp I ignored the
modernize-avoid-c-arrays one, mostly because making the sorts array an
std::array would most likely increase the code complexity because of the
virtual function. Aside from that, the static_cast warning from
Application.h was not dealt with, since it's not in this PR's scope.

launcher/modplatform/modrinth/ModrinthPackIndex.h

@@ -2,8 +2,8 @@
 
 #include "modplatform/ModIndex.h"
 
-#include <QNetworkAccessManager>
 #include "BaseInstance.h"
+#include <QNetworkAccessManager>
 
 namespace Modrinth {