QmakeProjectManager: Modernize more

Some files (mostly headers) were missing modernization for:

modernize-use-nullptr
modernize-use-override
modernize-use-using
modernize-use-default-member-init

Change-Id: I7027efac7daa3645af21ac25c0301105945e04da
Reviewed-by: Tobias Hunger <tobias.hunger@qt.io>

src/plugins/qmakeprojectmanager/wizards/qtprojectparameters.cpp

@@ -36,10 +36,7 @@ namespace QmakeProjectManager {
 namespace Internal {
 
 // ----------- QtProjectParameters
-QtProjectParameters::QtProjectParameters()
-  : type(ConsoleApp), flags(0), qtVersionSupport(SupportQt4And5)
-{
-}
+QtProjectParameters::QtProjectParameters() = default;
 
 QString QtProjectParameters::projectPath() const
 {