Emit a resized event on the resource preview when thumbnail resizes

* If the overall preview widget doesn't resize but the thumbnail does because
  the preview text label has changed in size, we should emit a resize event so
  the thumbnail can be redrawn.

qrenderdoc/Widgets/Extended/RDLabel.cpp

@@ -187,6 +187,7 @@ void RDLabel::resizeEvent(QResizeEvent *event)
     }
   }
 
+  emit resized();
   QLabel::resizeEvent(event);
 }
 

qrenderdoc/Widgets/Extended/RDLabel.h

@@ -48,6 +48,7 @@ signals:
   void doubleClicked(QMouseEvent *event);
   void mouseMoved(QMouseEvent *event);
   void leave();
+  void resized();
   void styleChanged(QEvent *event);
 
 public slots:

qrenderdoc/Widgets/ResourcePreview.cpp

@@ -96,6 +96,9 @@ void ResourcePreview::Initialise()
   QObject::connect(ui->slotLabel, &RDLabel::doubleClicked, this, &ResourcePreview::doubleClickEvent);
   QObject::connect(ui->descriptionLabel, &RDLabel::doubleClicked, this,
                    &ResourcePreview::doubleClickEvent);
+
+  if(m_ManualThumbnail)
+    QObject::connect(m_ManualThumbnail, &RDLabel::resized, [this]() { emit resized(this); });
 }
 
 ResourcePreview::~ResourcePreview()