Refs #11395

The converted text is stored in separate .rst files in the docs directory.
Refs #9562

(This change is a safe one to make as the property was essentially
mandatory anyway -- previously we were just checking in the `exec`
portion of the alg rather than in `init`.)

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

Notes:
- 4 classes weren't deleting the returned pointer
- more were not exception safe
- some changes rely on the move assignment operator for efficiency.

Notes:
- 4 classes weren't deleting the returned pointer
- more were not exception safe
- some changes rely on the move assignment operator for efficiency.

But there is subtle difference in reduction results

the difference does not have big physical sense, as the relative values of differences are small, but still unclear why it is present at all.

The CheckWorkspacesMatch got possibility to analyze relative error together with the absolute error to understand the difference better
LoadMask.cpp in the ISIS part has been changed to report loaded masks on debug level rather then notice as the messages in the log complicate understanding of what is going on.

LoadLOQDistanceFromRaw, LoadLog, LoadMappingTable,
LoadMask, LoadMaskingFile, LoadMuonLog, LoadNXSPE

re #6485

No unit test added so far.

SaveMaskTest uses LoadMask. Thus it is changed too.

Just renamed, but not modified.

Masking XML file's definition is changed.  So thus LoadMaskingFile() and
its unit test to implement the change.

In the latest definition of masking workspace, 0 and 1 are defined as
not masking and masking the workspace, respectively.  The following
codes are affected by the swtich of the definition of 0 and 1 on masking
or not.