Plot title and plot window title are not updated when renaming the workspace

[SilkeSchomann]

Describe the bug
Renaming the workspace does not have an impact on the plot title and plot window title of a slice plot.

Expected behavior
The plot window title of a slice plot should always get updated when the underlying workspace is renamed. The plot title it should get updated when the user has not changed the title, that is when the plot title is still the same as the previous workspace name.

Additional context
Mantid shows the correct behaviour for this.

[MialLewis]

Having spent a bit of time looking at this, I think this falls more under the feature category, and therefore should be developed after the feature freeze.

In Mantid renaming is handled via the ADS observers, which trigger renameHandle in the figuremanager, causing the titles etc, of related figures to be renamed.

As far as I can see, there doesn't seem to be any equivalent link (via observers or otherwise) between workspaces and figures in mslice. Hence a feature to create this link needs to be added. This could possibly be incorporated into the globalfiguremanager/observabledictionary

[SilkeSchomann]

Agreed. Will replace labels accordingly.