Changes at "User privacy options and ability to disable public profiles"

**Is your feature request related to a problem? Please describe.**

Some users are very cautious about their privacy and currently in Decidim it is not possible to create private user accounts. Once you create an account on the platform, it is public and available for everyone's eyes.

The person searching their name in Google (or other search engines) will find results on the Decidim platform. Some people are extremely worried about this functionality and some will even refuse to participate unless they can do it privately.

**Describe the solution you'd like**

I'd like to be able to configure whether the public profiles functionality is active or disabled on the platform. When disabled, the public profiles would not be accessible on the platform.

**Describe alternatives you've considered**

Creating a customization per instance but this exact same request comes to us every other month now, so I think it would be sensible to consider how to solve this properly.

Given the proposed functionality, this could be also a setting per profile but in that case it should be disabled by default and only if the user wants, their profile would become public.

**Additional context**

Especially in Finland people can be extremely cautious about entering their details into any web platforms or having their name appear on public websites where other people can inspect what their neighbor is doing.

Some people feel this is a violation of their personal privacy.

**Does this issue could impact on users private data?**

Yes, it has a positive impact on users' private data as their private data won't become publicly visible on a website without them having full control over it.

**Funded by**

We can possibly find funding for this if it is agreed on.