subcategory tags with manually entered special characters are rejected

[Cykotiq]

manually added game/subcategory tags containing special characters such as ' : ! & are rejected when validating, even though games pulled from the RAWG database are able to use those same characters. Unsafe characters should be stripped or converted to their equivalent html entities, rather than just refusing the tag

This has prevented streamers from adding legitimate games such as "Death's Door" or "The Simpsons: Hit & Run" to the list, with no understanding of why it fails.