Avoids progress reporting arrow overlapping the line numbers.

Python reports line numbers based on the code context it has. These
can be wrong if the selection is part of a larger file. Padding the code
then allows the raw numbers being reported to be used.

It uses a single QApplication object for the whole process rather than trying to
create an application for each test method

# Please enter a commit message to explain why this merge is necessary,
# especially if it merges an updated upstream into a topic branch.
#
# Lines starting with '#' will be ignored, and an empty message aborts
# the commit.

Merge done to enable documentation be be fixed, because of removal of
alias directive and addition of related algorithms directive.

Signed-off-by: Karl Palmen <karl.palmen@stfc.ac.uk>

Attempts to fix a random test failure with the jupyter console on
macOS by ensuring that widgets are garbage collected promptly.
Refs #22063

._update_indent() was changed not to take arguments and IPython.core.usage.quick_guide was removed.

In test_execute_async_returns_failure_on_runtime_error_and_captures_expected_stack the comment was causing an IndentationError, changing it to a docstring fixes the problem. I don't think this is related to IPython but probably a python 3.6 problem.

traceback.format_exception is supposed to ignore the tb argument if it is None but
in 3.4 the current traceback is always printed
https://github.com/python/cpython/commit/c3f417dc47b3a9564608c98cd176c530d9ebdf09#diff-e57ff53a569d0ebbe201ad0c102ee27e

Adds numpy and matplotlib to startup code.
Also silently executes a new interpreter as it starts so that the
completion api is populated.

Refs #21567

This required ensuring that the log diplay can have the correct default
priority.
Refs #21567

Fixes 2D plotting for WorkspaceGroups.
Refs #21567

This is just a thin wrapper around pcolormesh.
Refs #21567

Refs #21567

Refs #21567

Refs #21567

Refs #21566

This includes, adding functionality to give QAction an icon.

Refs #21592

Error bar curves are hidden from legends.
Also adds a title to the axes.
Refs #21567

Refs #21567

The string name of the class must be passed in or the registration has no effect in Python.

Refs #21567

Refs #21592

Refs #21592

Refs #21567

Refs #21567

Refs #21567

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Refs #21567

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Refs #21567