Add spaces between publisher elements

[jason-fox]

Description

Dublin Core rendering concatenates Organization and PrintLocation incorrectly if both elements are present. This PR adds a space between each element before normalizing whitespace.

Motivation and Context

Consider the following <Bookmap>

 <publisherinformation>
      <organization>Example Publishers</organization>
      <printlocation>Austin, TX</printlocation>
      <published>
        <publishtype value="general"/>
        <completed><year>1977</year></completed>
      </published>
    </publisherinformation>

This currently renders as:

<meta name="DC.publisher" content="Example PublishersAustin, TX1977">

It should render with a space between each element as:

<meta name="DC.publisher" content="Example Publishers Austin, TX 1977">

How Has This Been Tested?

Manual testing

Type of Changes

• Bug fix

Documentation and Compatibility

• What documentation changes are needed for this feature?
  (Provide links to existing documentation topics that will require updates)
• Will this change affect backwards compatibility or other users' overrides?

Checklist

• My code follows the code style of this project.
  • https://github.com/dita-ot/dita-ot/wiki/Java-Coding-Conventions
  • https://github.com/dita-ot/dita-ot/wiki/XSLT-Coding-Conventions
  • https://github.com/dita-ot/docs/wiki/coding-guidelines
• I have updated the unit tests to reflect the changes in my code.