Tag Essentials - with AI auto tagging and XFRM support 2.9.3

The Wiki page was very wasteful of space, so we've updated the layout from

to

Obviously, it looks much better.

• Fixed: viewing a tag didn't indicate if it was watched

Fix 'watch tag' button which didn't dynamically update itself like the 'watch thread' button does

- Fix incorrect "Some tags are not permitted in this forum" error when adding an existing tag.
With thanks to those who reported the issue

We showed a generic 'tag is blacklisted' type error when a tag was rejected. Now we have a more useful error message.
Also the logic for the setting Restrict addition of tag to threads in these forums for specific tags was not correct, so that's been fixed.

• Fix per-tag "Restrict addition of tag to threads in these forums" option being unexpectedly applied in some cases
• Fix behaviour of per-tag "Restrict addition of tag to threads in these forums" option to correctly apply the "none" option and to deselect if forums being applied when unchecked

Fix double-clicking unwatch in a row could cause a server error on the 2nd unwatch

• Fixed an issue with the minimum tag cloud widget size being 25 tags
• Made the tag cloud widget work on thread_view

File missing from the install zip of 2.3.6.

Fix "Illegal mix of collations" on MySQL 8+
Thanks to @Xon for the speedy fix.