Fix the title/body issue for todo apis when it is a duo todo

What does this MR do and why?

Fix the title/body issue for todo apis when it is a duo todo

• Duo todos, which are user based, do not answer to title that is called and exposed from body in the API layers. So we need to make a path here for body to answer for these.
• We'll do it in a targeted way here for duo, but if more user targeted todos are created, they will need accounted for as well.
• see #545208 (closed). This bug was introduced in Notify user via todo when they gain access to Duo (!177019 - merged)

Changelog: fixed EE: true

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Related to #545208 (closed)