They were saved at a time where a bug in the history saving
meant the files were extremely large and take a long time to load.
The history is not vital for the reference result
Refs #26639

Improves flexibility across instruments instead of writing
more code.
Refs #26639

The ISIS powder scripts are now in use for HRPD.

Refs #26639

https://bugs.python.org/issue9334

Exit whole system test process early with a failure code
if any errors occurred in setting up the tests to run

Slowed down the tests by a large amount

This reverts commit 956ac1d6.

The current tests produce files with the same name.
This keeps the tests from falling over on Windows when multiple tests try to remove the same file in clean up.

The documentation always claimed they were regexes but they
were not treated this way

optparse has been deprecated for sometime.
Hit files with YAPF

On Windows paths can contain escape characeters, such as '\t' in
'PythonInterface\test' that don't get recognized in the sys.path
correctly.

It helps in some circumstances where not all dependencies
are available.

All modules should be able to loaded cleanly so that errors can be picked
up rather than skipped

The testhelpers are now needed to see our implementation of the
faster numpy.testing.assert for numpy < 1.9

Refs #26262

Avoids a huge performance bottleneck when running the function
in a tight loop.

Refs #26349

Re #26259

It is unused as users how gone in a different direction
with the project.
Refs #26223