A previous PR added strict frontend and backend validation for tags that disallowed accented characters.
We're relaxing this restriction so that tags with non-ascii strings can be used.
For example, if you're publishing content in Spanish and want to make that more discoverable, you can tag the article with Español (this was an existing tag which was being used - you can see articles at https://dev.to/t/espa%C3%B1ol - but could not be added to new articles so all the content is from May 2020 or earlier).
A Portuguese speaking user recently reported issues importing articles from an external blog. This PR should also reduce errors importing articles from RSS Feeds when categories are labelled in non-ascii characters.
We still won't permit emoji or symbols in tag names, only words and letters. We tested against Polish, Chinese, and Arabic words to get a fair sample of different languages and scripts without an issue when adding this change.