Use USB manufacturer and product strings for names

The devices have their own name, in the form of USB manufacturer and
product string descriptors.  Now we use those in the GUI as the device
names.

data/pd-buddy-gtk.ui

                                   <object class="GtkLabel">
                                     <property name="visible">True</property>
                                     <property name="can_focus">False</property>
+                                    <property name="halign">start</property>
                                     <property name="label" translatable="yes">A</property>
                                   </object>
                                   <packing>
                                   <object class="GtkLabel">
                                     <property name="visible">True</property>
                                     <property name="can_focus">False</property>
+                                    <property name="halign">start</property>
                                     <property name="label" translatable="yes">V</property>
                                   </object>
                                   <packing>
                                     <property name="visible">True</property>
                                     <property name="can_focus">False</property>
                                     <property name="halign">start</property>
-                                    <property name="orientation">vertical</property>
-                                    <property name="layout_style">end</property>
+                                    <property name="layout_style">expand</property>
                                     <child>
                                       <object class="GtkToggleButton" id="giveback-toggle">
                                         <property name="label" translatable="yes">GiveBack</property>

pd-buddy-gtk.py

         self._builder.connect_signals(self)
 
         name = self._builder.get_object("name")
-        name.set_text(self.model.serport.description)
+        name.set_text('{} {}'.format(self.model.serport.manufacturer,
+                                     self.model.serport.product))
 
         device = self._builder.get_object("device")
         device.set_text(self.model.serport.device)
         # Show the Sink page
         hst = self.builder.get_object("header-stack")
         hsink = self.builder.get_object("header-sink")
+        hsink.set_title('{} {}'.format(serport.manufacturer, serport.product))
         hsink.set_subtitle(serport.device)
         hst.set_visible_child(hsink)