Fit Add Peak cursor does not survive moving off plot

[DanielMurphy22]

Noticed related to https://github.com/mantidproject/mantid/issues/31319

Describe the bug Fit Add Peak cross cursor does not survive moving off and back on to the plot.

To Reproduce Open MantidWorkbench CreateSampleWorkspace Plot a spectrum from the workspace click Fit in the plot toolbar right-click on the plot and select "Add Peak" and the cursor changes to a square If the mouse is moved off the plot or onto the FitpropertyBrowser then the cursor reverts to the default and you cannot add the peak

Expected behavior Cursor is a cross after the Add Peak button is selected and stays a cross (when over the plot) until a Peak is added. Also the mouse can be moved off the plot and back and still be able to add the peak! After the peak is added the cursor reverts to the default and the ability to add a peak is disabled.

Platform/Version (please complete the following information):

• Found on OSX and Ubuntu