Replaces the customer's tags with the list you send. It doesn't add to the existing tags.

• Any tag you leave out is removed. To add a tag, send the current tags plus the new one.
• Send an empty array to remove every tag. Always send an array: null or any other value also removes every tag, and a comma-separated string is split into separate tags.
• A tag that doesn't exist yet is created on your profile.
• Tags are trimmed and duplicates are removed. The order isn't kept.
• A tag that matches an existing tag, ignoring case, is saved with the existing spelling. The response can still show your spelling. List customer tags shows the saved one.
• If the customer's saved details are invalid, you get 422 and the tags aren't changed. Fix the customer first.