Wire Sud upload/download into the brewpi_gui client

Adds File menu actions to save the running Sud's schedule to a local
sud.json and to replace it from one, via the Sud websocket channel's
new Download/Upload messages. File dialogs are opened up front on the
GUI thread; the actual read/write happens off the websocket recv
callback, which runs on a worker thread and must not touch Qt itself.

main_window.py is regenerated from brewpi.ui via pyuic5 5.15.11, which
also picks up an unrelated pre-existing drift (the default URI had
fallen out of sync with the .ui source).

client/main_window.py

@@ -2,7 +2,7 @@
 
 # Form implementation generated from reading ui file 'brewpi.ui'
 #
-# Created by: PyQt5 UI code generator 5.15.10
+# Created by: PyQt5 UI code generator 5.15.11
 #
 # WARNING: Any manual changes made to this file will be lost when pyuic5 is
 # run again.  Do not edit this file unless you know what you are doing.
@@ -1240,6 +1240,12 @@ class Ui_MainWindow(object):
         self.actionPause.setObjectName("actionPause")
         self.actionStop = QtWidgets.QAction(MainWindow)
         self.actionStop.setObjectName("actionStop")
+        self.actionSudDownload = QtWidgets.QAction(MainWindow)
+        self.actionSudDownload.setObjectName("actionSudDownload")
+        self.actionSudUpload = QtWidgets.QAction(MainWindow)
+        self.actionSudUpload.setObjectName("actionSudUpload")
+        self.menu_File.addAction(self.actionSudDownload)
+        self.menu_File.addAction(self.actionSudUpload)
         self.menubar.addAction(self.menu_File.menuAction())
         self.menubar.addAction(self.menu_Help.menuAction())
         self.toolBar.addAction(self.actionStart)
@@ -1272,7 +1278,7 @@ class Ui_MainWindow(object):
         self.label_5.setText(_translate("MainWindow", "Power [W]"))
         self.label_7.setText(_translate("MainWindow", "State"))
         self.label_state.setText(_translate("MainWindow", "State"))
-        self.plainTextUri.setPlainText(_translate("MainWindow", "ws://localhost:8765"))
+        self.plainTextUri.setPlainText(_translate("MainWindow", "ws://brewpi:8765"))
         self.label_8.setText(_translate("MainWindow", "Host"))
         self.menu_File.setTitle(_translate("MainWindow", "&File"))
         self.menu_Help.setTitle(_translate("MainWindow", "&Help"))
@@ -1284,3 +1290,7 @@ class Ui_MainWindow(object):
         self.actionPause.setToolTip(_translate("MainWindow", "Pause"))
         self.actionStop.setText(_translate("MainWindow", "Stop"))
         self.actionStop.setToolTip(_translate("MainWindow", "Stop"))
+        self.actionSudDownload.setText(_translate("MainWindow", "&Download Sud..."))
+        self.actionSudDownload.setToolTip(_translate("MainWindow", "Save the running Sud\'s schedule to a local sud.json"))
+        self.actionSudUpload.setText(_translate("MainWindow", "&Upload Sud..."))
+        self.actionSudUpload.setToolTip(_translate("MainWindow", "Replace the running Sud\'s schedule with a local sud.json"))