Read the *Work fields from XER files

[Petr Janeček]

As far as I can see, the getPlannedWork() method currently only works for P6 XML files, but it does not read anything for XER files even though there is data in the relevant fields (target_work_qty atc.)

Would it be possible to add XER support to read the labor / non-labor units? (Ideally as separate fields, see #664)

(EDIT: I mistakenly referenced the SUMTASK table in the original description, that's just wrong. I fixed the desc.)

[Petr Janeček]

Closing. The reader DOES provide the plannedWork() field via the target_work_qty column from XER.

The thing that threw me off, and what I think IS happening, though, is that XER reads the target_work_qty field (containing plannedLaborUnits), but XML reads plannedLaborUnits + plannedNonLaborUnits.

I'll verify and create a separate ticket.