Convert macros from plain QByteArray to a vector of structs

The old code model expected the macros as C++ formatted text
("#define Foo 42) but newer targets like the Clang codemodel expect key
value arguments like "-DFoo=42". So instead of parsing the text again and
again we use an abstract data description.

Task-number: QTCREATORBUG-17915
Change-Id: I0179fd13c48a581e91ee79bba9d42d501c26f19f
Reviewed-by: Tobias Hunger <tobias.hunger@qt.io>

src/plugins/cpptools/cpprawprojectpart.cpp

@@ -81,9 +81,9 @@ void RawProjectPart::setQtVersion(ProjectPart::QtVersion qtVersion)
     this->qtVersion = qtVersion;
 }
 
-void RawProjectPart::setDefines(const QByteArray &defines)
+void RawProjectPart::setMacros(const ProjectExplorer::Macros &macros)
 {
-    this->projectDefines = defines;
+    this->projectMacros = macros;
 }
 
 void RawProjectPart::setHeaderPaths(const ProjectPartHeaderPaths &headerPaths)