[ENH] User mention notifications : Send a notification when a user is mentioned in a wiki page comment

Avan.tech ticket: https://avan.tech/item83046

Send a notification to the user mentioned in a comment on a wiki page.

added 16 commits

• 67374208...d0dc2077 - 15 commits from branch tikiwiki:master
• 4c783bc9 - [ENH] User mention notifications : Send a notification when a user is...

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merged