* Fix for #2488 - parse contents of search results of type=Category (returned on first page for universal (type=all) queries instead of returning an error.
* Moved content array walker to Category#to_json
As requested by reviewer this change moves the content array walker from the API endpoint to the Category class.
* Update src/invidious/helpers/serialized_yt_data.cr
Co-authored-by: syeopite <70992037+syeopite@users.noreply.github.com>