Add plotting widget

[StephenNneji]

• Adds plot widget Closes Create plotting widget #30
• Move saving of result to a command
• I also removed parents i.e. super().__init__(parent) from the mdi widgets to avoid the issue I was experiencing on Windows 11 where the widget gets added to the Mainwindow, it turns out the widgets are reparented when we added them to the mdi area so setting the initial parent was not needed.

[alexhroom]

looks good and works great, mostly just documentation changes needed. some wider points:

• at least for now while plotting is slow, it would be good to be able to toggle live plotting on or off as it drastically slows down the run!

• this is minor but it would also be nice if we could use a consistent name for the plotting: we currently have
  view.terminal_widget holds a TerminalWidget found in terminal.py
view.project_widget holds a ProjectWidget found in project.py
view.controls_widget holds a ControlsWidget found in controls.py
  but
  view.plotting_widget holds a PlotWidget found in plotter.py
  i think it'd be less complex for dev cognitive load if it could consistently be either plotting, plot or plotter

[StephenNneji]

• I have renamed the plotting to plot
• As for stopping the live plot you can set the updatePlotFreq in controls to zero.

[alexhroom]

ah sorry i forgot about updatePlotFreq! looks good to me