Update to clang-format-5 and reformat the codebase 

This was a request after seeing #23083.

MSVC 2017 15.7 contains a bug where constant initialization no longer
takes place for objects with constructors marked constexpr such as
once_flag. This leaves once_flag susceptible to dynamic initialization
order problems and causes some singleton instances to be constructed
incorrectly. We put back our correct implementation (with some cleanup)
and await a fix from MS.
Refs #0

re #23102

re #23102

re #23102

Refs #0

Something changed in VS2017 such that SingletonHolder::once_flag
was not always initialized before SingletonHolder::instance and
this caused multiple singleton instances to be created. In some
ways this was a timebomb as static initialization order is
undefined.

Previously getObjects in the ADS returned hidden workspaces
conditionally depending on the config setting. This commit adds an
option building on previous work completed in getObjectNames().

Allowing callers to specify whether to include hidden workspaces is
required for project recovery. The hidden workspace history can then be
saved out

Refs #22739

re #22553

re #22553
Added extra tests to create numpy arrays from return values

re #22553

re #22553

re #22553

re #22553

re #22553

re #22553
The free function reduces code duplication and is slightly
cleaner to use.

This is code duplicated in GroupDetectors and ReflectometryReductionOne2.

Re #22315

This includes dragging the libcxx implementation of normal_distribution
and uniform_int_distribution into our source. MSVC, clang and gcc don't
agree on how this should be implemented leading to problems with
comparing test results across platforms. Using a single implementation
gives the same results on each platform.