Merge branch '25172_erroneous_negative_peaks_in_phase_quad' of https://github.com/mantidproject/mantid into 25172_erroneous_negative_peaks_in_phase_quad

Turn off X errorbars in workbench plots

Workbench: User aimed documentation

Double-clicking algorithm opens run dialog in Workbench

Replace 'execute' with 'open_run_dialog' to avoid confusion.

re #25180

Move the AlgorithmProgress widget to C++

Fix ORNL SANS setup workflow algorithms

SNSPowderReduction fixes

Python algorithm properties declare ints as C longs. Specializations
for the JSON decoder were missing for this and a few other types.
Refs #25138

Show log value in viewer

Mock out threading in unit tests

Dimitar Tasev authored Mar 13, 2019 and Gigg, Martyn Anthony committed Mar 15, 2019

Now uses a single ProgressObserver that oversees all events. This makes
the event triggering synchronous - no two events can trigger at the same time.

Handling an event requires changes in the GUI thread. Whenever an event
triggers, a QueuedConnection signal is emitted to the GUI. This queues
an update that will be done at some point in the future event loops.