CMakePM: Refactor "Initial Parameters" as a tab bar item

Now we have "Initial Configuration" and "Current Configuration"
as tab bar buttons.

This way the UI can be shared between the two configuration states.

Task-number: QTCREATORBUG-26869
Change-Id: I8206032a2a5ac076629865057816edb99706f2ff
Reviewed-by: <github-actions-qt-creator@cristianadam.eu>
Reviewed-by: Eike Ziller <eike.ziller@qt.io>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>

src/plugins/cmakeprojectmanager/cmakebuildsystem.h

@@ -108,6 +108,9 @@ public:
 
     CMakeProject *project() const;
 
+signals:
+    void configurationCleared();
+
 private:
     // Actually ask for parsing:
     enum ReparseParameters {
@@ -123,7 +126,7 @@ private:
     void setParametersAndRequestParse(const BuildDirParameters &parameters,
                                       const int reparseParameters);
 
-    bool mustApplyExtraArguments(const BuildDirParameters &parameters) const;
+    bool mustApplyConfigurationChangesArguments(const BuildDirParameters &parameters) const;
 
     // State handling:
     // Parser states: