Structure Factor estimator at unit test stage

[PDoakORNL]

Proposed changes

This add the actual batched Structure Factor Estimator. It should cover the functionality of the skAll and static structure factort estimators from the legacy code. This is just the estimator and unit tests it does not include integration with the EstimatorManagerNew or processing of structurefactor input at the application level.

That will be added in a following PRs.
What type(s) of changes does this code introduce?

Delete the items that do not apply

New feature
Build related changes
Testing changes (e.g. new unit/integration/performance tests)
Documentation or build script changes

Does this introduce a breaking change?

No

What systems has this change been tested on?

sdgx2
Checklist

Update the following with a yes where the items apply. If you're unsure about any of them, don't hesitate to ask. This is
simply a reminder of what we are going to look for before merging your code.

Yes This PR is up to date with current the current state of 'develop'
Yes Code added or changed in the PR has been clang-formatted
Yes This PR adds tests to cover any new code, or to catch a bug that is being fixed
Yes Documentation has been added (if appropriate)

[ye-luo]

Source code seems OK. but need to fix the CI failure.

[PDoakORNL]

Working to understand the CI failure.

[PDoakORNL]

Fixed all the subtleties with clang but gcc still gets quite different values.

[PDoakORNL]

Reproduced the gcc failures...