Support for string arrays

[isosc]

This is a followup on a discussion with @williamfgc and @pnorbert about adding support for string arrays (vector of strings, numpy array). The primary need is to extend the C++ API to support put and get of vectors of strings. Once that exists, extending this functionality into Python should be straightforward.

One design issue is how to serialize and deserialize this data structure to BP. We discussed a tentative strategy which involved storing a list of string sizes followed by the collapsed string data.

[eisenhauer]

Just a note, this is very straightforward with the FFS marshaling employed by default in SST as the lower layer supports marshaling general pointer-based data structures. So as soon as the C++ API is set, I'd just need to tweak the data type conversions and it pretty much falls out.

[williamfgc]

Is this available on BP5 or in the roadmap?