Split tx dialog buttons

The "actions" (sign, broadcast, send to cosigner, verify GA instant)
go on the RHS next to the "Cancel" button.

Copy, QR code and save go on the left.

plugins/cosigner_pool.py

@@ -115,7 +115,7 @@ class Plugin(BasePlugin):
     def transaction_dialog(self, d):
         self.send_button = b = QPushButton(_("Send to cosigner"))
         b.clicked.connect(lambda: self.do_send(d.tx))
-        d.buttons.insert(2, b)
+        d.buttons.insert(0, b)
         self.transaction_dialog_update(d)
 
     @hook