Continue device connection with empty/null objectName prop

[gnmerritt]

We were missing a whole bunch of devices at a site, turns out a number of the controllers there don't reliably report objectName. This fixes the connect logic to continue regardless, which allows us to pull the point list for devices with no name.

[gnmerritt]

Also added a fix to stop a ValueError when presentValue comes back as an empty string. This was stopping point discovery for us in some cases too

[ChristianTremblay]

Clearly you've got some very ackward devices...
It won't create issues on good devices so let's merge

Thanks @gnmerritt