fix: disable move in generated adaptor and proxy classes (#435)

Moving adaptor or proxy instances changes their `this` pointer. But `this` is captured by value in closures used by those instances, and this remains unchanged on move, leading to accessing an invalid instance when a lambda expression executes. Supporting move semantics would require unsubscribing/unregistering vtable, handlers, etc. and re-subscribing and re-registering all that, which is too complicated and may have side effects. Hence it has been decided that these classes are not moveable. One may use an indirection with e.g. `std::unique_ptr` to get move semantics.

examples/org.freedesktop.DBus.ObjectManager/examplemanager-planet1-client-glue.h

@@ -21,14 +21,14 @@ public:
 
 protected:
     Planet1_proxy(sdbus::IProxy& proxy)
-        : proxy_(&proxy)
+        : m_proxy(proxy)
     {
     }
 
     Planet1_proxy(const Planet1_proxy&) = delete;
     Planet1_proxy& operator=(const Planet1_proxy&) = delete;
-    Planet1_proxy(Planet1_proxy&&) = default;
-    Planet1_proxy& operator=(Planet1_proxy&&) = default;
+    Planet1_proxy(Planet1_proxy&&) = delete;
+    Planet1_proxy& operator=(Planet1_proxy&&) = delete;
 
     ~Planet1_proxy() = default;
 
@@ -40,18 +40,18 @@ public:
     uint64_t GetPopulation()
     {
         uint64_t result;
-        proxy_->callMethod("GetPopulation").onInterface(INTERFACE_NAME).storeResultsTo(result);
+        m_proxy.callMethod("GetPopulation").onInterface(INTERFACE_NAME).storeResultsTo(result);
         return result;
     }
 
 public:
     std::string Name()
     {
-        return proxy_->getProperty("Name").onInterface(INTERFACE_NAME).get<std::string>();
+        return m_proxy.getProperty("Name").onInterface(INTERFACE_NAME).get<std::string>();
     }
 
 private:
-    sdbus::IProxy* proxy_;
+    sdbus::IProxy& m_proxy;
 };
 
 }}} // namespaces