Read username and password from environment variables

[olli-acterglobal]

Summary

Let us specify MATOMO_SUPERUSER_USERNAME and MATOMO_SUPERUSER_PASSWORD as environment variable, and let it pre-fill the setup wizard, like we can database settings.

Justification

I am writing an ansible role that automatically provisions matomo.
Since ansible has facilities to securely store passwords, it would be convenient to be able to pass the password through an environment variable.
There exists a plugin, but I'd rather just rely on the official featureset here.

Related issues

#10914
#13676

[des-innocraft]

Hi @olli-acterglobal ,
Thank you for bringing this to our attention and for your valuable input. Your suggestion seems like a valuable enhancement to our product.

We will forward this to our Product team for review and future consideration.

If you have any additional details or questions, please feel free to share them here.

[sgiehl]

refs #10257