Unsupported instruments in DrILL

Adds a check on the selected algorithm when opening the settings dialog.
This avoids a crash if an unsupported instruments has been selected.

Log an error if the user changes the facilty and DrILL is shown.

The connection to the instrument selector widget is removed when the
DrILL interface is closed. That avoids error messages coming from the
interface when it is not

Removes the filering of instruments in the instrument selector widget of
DrILL. This avoids a wrong instrument selection in DrILL if the user
selected an unsupported instrument in workbench global settings.

Geometry code cleanup

Add separate page for Sliceviewer release notes

Format release notes for 5.1.0 Diffraction, Muons, LSS and Spec

Co-authored-by: DanielMurphy22 <daniel.murphy@stfc.ac.uk>

Refs #29325. Enable workbench to have plot menu for MDHistoWorkspace.

Co-authored-by: DanielMurphy22 <daniel.murphy@stfc.ac.uk>

Merge branch '29325_workbench_plot_md' of github.com:mantidproject/mantid into 29325_workbench_plot_md

Remove profiling section to prevent confusion in Basic Course

Reorganise Core Release Notes and Add Images

Remove Qt.EnableHighDPIScaling attribute