CMakeProcess: Don't use QTimer for checking the canceled state

Create a QFutureWatcher instead and connect to its canceled()
signal.

Replace some includes with forward declarations.

Change-Id: Ie82bf8902ef8c8d87011809bd14b7db3d4f52179
Reviewed-by: <github-actions-qt-creator@cristianadam.eu>
Reviewed-by: Cristian Adam <cristian.adam@qt.io>

src/plugins/cmakeprojectmanager/fileapireader.h

@@ -25,8 +25,8 @@
 
 #pragma once
 
+#include "builddirparameters.h"
 #include "cmakebuildtarget.h"
-#include "cmakeprocess.h"
 #include "cmakeprojectnodes.h"
 #include "fileapidataextractor.h"
 
@@ -49,6 +49,7 @@ class ProjectNode;
 namespace CMakeProjectManager {
 namespace Internal {
 
+class CMakeProcess;
 class FileApiQtcData;
 
 class FileApiReader final : public QObject