Support _sort with _include and _revinclude

[lmsurpre]

Is your feature request related to a problem? Please describe.
In SearchUtil.java we have the following code snippet:

if (queryParameters.containsKey(SearchConstants.INCLUDE)
                || queryParameters.containsKey(SearchConstants.REVINCLUDE)) {
            // Make sure _sort is not present with _include and/or _revinclude.
            // TODO: do we really need to forbid this?
            if (queryParameters.containsKey(SearchConstants.SORT)) {
                throw SearchExceptionUtil.buildNewInvalidSearchException(
                        "_sort search result parameter not supported with _include or _revinclude.");
            }

I think we made that simplifying assumption when this was first implemented; we weren't sure what the proper behavior would be (should the sort apply to the include resources or just the match resources?).

Now I'm pretty confident that it should only apply to the match resources and I think we should be able to support these parameters when used in combination.

Describe the solution you'd like
Apply the _sort to the search so that we get the first _count target resources that match the query. Then add in the include/revinclude resources for this page of results.

Describe alternatives you've considered
Continue to disable the use of these parameters together.

Additional context

[lmsurpre]

I verified this via the following queries in our connectathon environment:

{{baseUrl}}/ExplanationOfBenefit?_include=ExplanationOfBenefit:*&_sort=_lastUpdated&_elements=meta
returned 4 EOB resources, properly sorted by their Resource.meta.lastUpdated values, followed by included Coverage, Organization, and Patient resources.

{{baseUrl}}/ExplanationOfBenefit?_include=ExplanationOfBenefit:*&_sort=-_lastUpdated&_elements=meta
returned 4 EOB resources, reverse sorted by their Resource.meta.lastUpdated values, followed by included Coverage, Organization, and Patient resources.