[IMP] website_forum : Karma check for tag creation and follow tag mechanism

Hello,

->  It will allow user to follow/unfollow Tag.
->  It will also check Tag case sensitivity and uniqueness.

More Details:
Task: https://www.odoo.com/web#id=8318&view_type=form&model=project.task&action=327
pad: https://pad.odoo.com/p/r.ePTaRKLxamjWaWAZ

Thanks
jas-odoo
You should add an unique constraint on tags (beware to uppercase/lowercase and accents), to protect at model level the duplication of tags. When creating a new post (question or answer), handle the error about tags in the controller instead of doing it in js. Like said in other comments, this does not protect against different users creating duplicated tags.