monitor: mutations

[oliver-sanders]

Follow-on from #3463

Attempt after/with #2123

Good low-priority rainy-day/jetlag activity.

Add mutations to cylc monitor e.g. trigger task:

• Should be fairly quick as the mutation interfaces should be auto-generated.
• We should be able to get a list of mutations applicable to a tree node by instrospecting the GraphQL schema.
• We can overlay menu interfaces with urwin example:

class MonitorTreeBrowser:

    def menu(self):
        overlay = urwid.Overlay(
            urwid.AttrMap(
                urwid.Padding(
                    urwid.ListBox(
                        urwid.SimpleFocusListWalker([
                            urwid.Text('Hello Menu!'),
                            urwid.Divider(),
                            urwid.AttrMap(
                                urwid.Button('Abc'),
                                'button',
                                focus_map='reversed'
                            ),
                            urwid.AttrMap(
                                urwid.Button('Bcd'),
                                'button',
                                focus_map='reversed'
                            )
                        ])
                    ),
                    left=2,
                    right=2
                ),
                'menu'
            ),
            self.loop.widget,
            align='center',
            width=('relative', 60),
            valign='middle',
            height=('relative', 60),
            min_width=20,
            min_height=5
        )
        self.loop.widget = overlay

    def unhandled_input(self, k):
        if k in ('q','Q'):
            raise urwid.ExitMainLoop()
        if k == 'a':
            return self.menu()

Pull requests welcome!

[oliver-sanders]

Closed by #3557