Add whitespace normalization to the EML previewer

[rogerdahl]

The EML previewer may not display the exact same results as those shown in the metadata viewer after a package has been uploaded, as the previewer does not apply the whitespace normalization that is a step in creating the Level-1-EML.xml that is displayed after package upload.

Also make sure that any other formatting steps that are performed when creating the Level-1-EML.xml are included in the previewer. Ideally, refactor the two methods to one.