Move mimetype definitions to plugin specs

- Avoids the hassle of QRC files and manually registering mime types
- Avoids performance regressions because of mime types that are
  registered after mime database has been used
- Makes it technically possible to detect that a disabled plugin could
  handle a mime type if it was enabled

Change-Id: I373008b1b56e9c6b4853055f20b3eeb112a6eff9
Reviewed-by: Christian Stenger <christian.stenger@qt.io>
Reviewed-by: hjk <hjk@qt.io>

src/plugins/cmakeprojectmanager/cmakeprojectplugin.cpp

@@ -47,7 +47,6 @@
 #include <projectexplorer/kitmanager.h>
 #include <projectexplorer/projecttree.h>
 
-#include <utils/mimetypes/mimedatabase.h>
 #include <utils/parameteraction.h>
 
 using namespace CMakeProjectManager::Internal;
@@ -59,8 +58,6 @@ bool CMakeProjectPlugin::initialize(const QStringList & /*arguments*/, QString *
     Q_UNUSED(errorMessage)
     const Context projectContext(Constants::PROJECTCONTEXT);
 
-    Utils::MimeDatabase::addMimeTypes(QLatin1String(":cmakeproject/CMakeProjectManager.mimetypes.xml"));
-
     Core::FileIconProvider::registerIconOverlayForSuffix(Constants::FILEOVERLAY_CMAKE, "cmake");
     Core::FileIconProvider::registerIconOverlayForFilename(Constants::FILEOVERLAY_CMAKE, "CMakeLists.txt");