[enhancement] Add an option to allow anonymous access to a project

[NG-GOM]

Currently, having a user account is mandatory to access any of the platform functionalities.
It could be interesting to have an option to allow access to a project (or even to some specific metrics) to anonymous users.

For example, in our context, there's too many users to manually create/manage an account for each of them on every single integration tool and network we have ; thus we have "publicly" accessible data on our integration tools, so users do not have to identify to view most of the metrics. Some specific users still have accounts on some integration tools to execute management/administration tasks.