Refs #10238 Remove unneeded virtual keywords

These won't be inherted. They don't need to be virtual.
Refs #10238 Add plotWorkspaces method to QtReflMainView
Refs #10238 Add plotting actions to Refl UI
Refs #10238 Implement plotting in Refl UI
Refs #10238 Support multi-run rows for group plotting
Refs #10238 Document new plot actions
Refs #10238 Don't attempt to plot non-existant workspaces
Refs #10238 Warn when plotting unprocessed rows
Refs #10238 Test plotting warnings
Merge remote-tracking branch 'origin/feature/10238_refl_ui_plot_actions'