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/libs/extensionsystem/pluginspec_p.h

@@ -82,6 +82,7 @@ public:
     QString category;
     QRegExp platformSpecification;
     QVector<PluginDependency> dependencies;
+    QJsonObject metaData;
     bool enabledBySettings = true;
     bool enabledIndirectly = false;
     bool forceEnabled = false;
@@ -104,7 +105,7 @@ public:
 
     void enableDependenciesIndirectly();
 
-    bool readMetaData(const QJsonObject &metaData);
+    bool readMetaData(const QJsonObject &pluginMetaData);
 
 private:
     PluginSpec *q;