CMake: Use setup functions for more plugin items

Change-Id: I48ff764248f29ef2a8f46757cba84705983c7740
Reviewed-by: <github-actions-qt-creator@cristianadam.eu>
Reviewed-by: Jarek Kobus <jaroslaw.kobus@qt.io>

src/plugins/cmakeprojectmanager/cmakeformatter.h

@@ -4,14 +4,8 @@
 
 #pragma once
 
-namespace Core { class IDocument; }
-
 namespace CMakeProjectManager::Internal {
 
-class CMakeFormatter
-{
-public:
-    CMakeFormatter();
-};
+void setupCMakeFormatter();
 
 } // CMakeProjectManager::Internal