Feature: SERAC - editing possibilities for anonyme reports

[AntoineMarnat]

Community discussion about this feature (mandatory)
Link to https://forum.camptocamp.org/t/ticket-github-en-francais-et-pour-les-nuls/330402/3 where this feature has been discussed.

Is your feature request related to a problem? Please describe.
When a SERAC report is created and set to be anonymous, the creator can not edit it afterwards and there is no way to contact him even for moderators.

Describe the solution you'd like
For anonymous contributions, display « anonymus contributor » but allow the creator to edit the report, and allow moderators to contact the author (without displaying its identity).