Remove extra empty form fields

Created by: whunter

Don't render "extra" empty form fields.

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JIRA Ticket: (https://webapps.es.vt.edu/jira/browse/LIBTD-1331) ()

What does this Pull Request do? ()

Prevents "extra" empty text fields for multi valued attributes from being rendered in forms

What's the changes? ()

• Doesn't add empty entry to the end of collection that is used to build multi-valued text fields unless there is no pre-populated value

How should this be tested?

• Create a Composition
• Edit Composition
• Create a Performance
• Edit Performance
• Create Collection
• Edit Collection
• Check to make sure that no attribute has more than one empty text field.