Fix rendering of an empty page

[dannon]

… by ensuring default content, even if empty -- the undefined that comes through otherwise blows up the page initialization. This data management approach could use an overhaul when we modernize the component, but this is the quick fix.

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• I've included appropriate automated tests.
• This is a refactoring of components with existing test coverage.
• Instructions for manual testing are as follows:
  1. [add testing steps and prerequisites here if you didn't write automated tests covering all your changes]

License

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[mvdbeek]

Did you want this to go to 23.1 ?

[dannon]

@mvdbeek Yeah, I should have targeted there I guess. I'll open a backport -- thanks!