Better handling of empty TEI or CSV entries

[karindalziel]

sometimes a TEI element is blank, and sometimes there's an inadvertent space in a spreadsheet. When that happens we get a "No Label" entry on the orchid side

a better default would probably be to look for empty items (once all newlines, spaces, and tabs are stripped out) and then post.

We could use active support and the .blank? method, but I have a function to do it as well:

 def empty_post(field)
    unless field.to_s.strip.empty?
      field
    end
  end

[wkdewey]

This also came up with Habeas Corpus, some entries were coming up as "-".

[wkdewey]

I addressed this by changing the get_text and get_list methods (which use Nokogiri to query the XML) to return nil instead of blank when the xpath does not match. However, this still requires nil checks in the data repos and is a breaking change.