BUG Array to String conversion in $x_path utilization

[muskie9]

Summary

With allowing the declaration of the element classes to use when querying using DOMXPath, it seems that there is no iteration over the provided values. This causes an array to string conversion error. In our particular instance this is with running a variant to the GenerateSearchDocument in which we implemented generators for loops as we have a large number of records to iterate over.

I'm still working through fully confirming this and testing some local code to resolve, however altering portions of SearchDocument::makeSearchContent() to check for the type of $x_path for being an array and iterating seems to alleviate the error currently.

A PR will be issued if we can narrow this down further as we have come across additional errors that we will attach to this ticket or open additional tickets if not directly related.

Cheers!