getLocalizedData in ModelWithSettings does not fallback when a translation is missing

[kaitlinnewson]

Describe the bug
In ModelWithSettings.php, getLocalizedData() does not fallback to the first available piece of data when a translation is missing, so a null value may be used when a fallback is available. This is different from the behaviour in the DataObject implementation.

To Reproduce
Steps to reproduce the behavior:

1. Have a journal with multiple languages enabled
2. Enable announcements in the journal
3. Create the announcement in one language only and publish it
4. In the front-end, view the announcement and toggle between languages, noting that the title appears empty in languages where it was not translated

What application are you using?
OJS, OMP or OPS version main

Additional information

• DataObject implementation of getLocalizedData() for comparison:

  pkp-lib/classes/core/DataObject.php

  Lines 71 to 78 in 10e1b13

  	public function getLocalizedData(string $key, ?string $preferredLocale = null, ?string &$selectedLocale = null): mixed
  	{
  	$value = $this->getData($key);
  	if (!is_array($value)) {
  	return $value;
  	}
  	return $this->getBestLocalizedData((array) $this->getData($key), $preferredLocale, $selectedLocale);
  	}

• getBestLocalizedData():

  pkp-lib/classes/core/traits/LocalizedData.php

  Lines 31 to 49 in 10e1b13

  	protected function getBestLocalizedData(array $data, ?string $preferredLocale = null, ?string &$selectedLocale = null): mixed
  	{
  	foreach ($this->getLocalePrecedence($preferredLocale) as $locale) {
  	if (!empty($data[$locale])) {
  	$selectedLocale = $locale;
  	return $data[$locale];
  	}
  	}
  	// Fallback: Get the first available piece of data.
  	foreach ($data as $locale => $dataValue) {
  	if (!empty($dataValue)) {
  	$selectedLocale = $locale;
  	return $dataValue;
  	}
  	}
  	return null;
  	}

PRs
pkp-lib --> #10785
ojs --> pkp/ojs#4585 [TEST ONLY]

[touhidurabir]

@Vitaliy-1 can you please review the PRs at #10690 (comment) .