Docker: Rework auto-detection and removal of kit items

- Use more uniform messages for the different kinds of items
- Remove all auto-detected items

Change-Id: I0b0df0bca484337039432b163bd8e19593b1cd22
Reviewed-by: Christian Stenger <christian.stenger@qt.io>

src/plugins/debugger/debuggeritemmanager.h

@@ -53,7 +53,9 @@ public:
     static void deregisterDebugger(const QVariant &id);
 
     static void autoDetectDebuggersForDevice(const Utils::FilePath &deviceRoot,
-                                             const QString &detectionSource);
+                                             const QString &detectionSource,
+                                             QString *logMessage);
+    static void removeDetectedDebuggers(const QString &detectionSource, QString *logMessage);
 
     static const DebuggerItem *findByCommand(const Utils::FilePath &command);
     static const DebuggerItem *findById(const QVariant &id);