Extended submission does not include formVersion

[matthew-white]

Submission responses have a property named currentVersion, which is a submission version object. If extended metadata is requested, a submitter property is added to currentVersion, which matches what we do for extended submission version objects. However, a formVersion property is not added to currentVersion. Typically extended submission version objects have a formVersion property. If extended metadata is requested, I think it'd be ideal if the currentVersion property had all the properties of an extended submission version object. (I think formVersion is the only property it's missing.)