update all datamgmt functions to be compatible wth EML2

[jeanetteclark]

I think the main issue with this function is actually load_EML_units breaking.

this call: unitList_nS <- EML::get_unitList(x = EML::read_eml(system.file("share/EML-nS-unitDictionary.xml", package = "datamgmt"))) returns an empty list.

I believe you could just get the units from x$unit - bypassing the EML::get_unitList call entirely.

[jeanetteclark]

I took a quick stab at it with 410bdee on a branch but it probably (definitely) needs to be looked at more closely

[jagoldstein]

We need all the datamgmt functions updated to be compatible with the EML2 syntax before the latter package is installed, loaded, and adopted for use on the Datateam server.