The purpose of the class [JsonStringReader](https://github.com/wmde/FundraisingFrontend/blob/master/src/Infrastructure/JsonStringReader.php) is to read JSON files from the i18n directory and return the raw JSON as a string, while internally validating it. This approach is wasteful, since it runs json_decode on every request that uses the files, immediately dropping the decoded result. This kind of check would be placed better in the CI for fundraising-frontend-content.

Acceptance Criteria

• Add the check for validity and non-empty array/object structure to the drone tasks in fundraising-frontend-content
• In FunFunFactory, replace calls to JsonStringReader::readAndValidateJson with (new SimpleFileFetcher())->fetchFile('filename') (Lines 649ff).

Implementation Notes

• The drone task should create a GitHub issue if it fails.