Add user restrictions

[acelaya]

Summary

In preparation for the removal of API key roles and restrictions in Shlink 6.0.0, add an alternative way to restrict what managed users can see by setting-up restrictions:

• See stuff for only one of the server's domains.
• See stuff that was created with one specific API key (the one associated with the server).
• Restrict access to orphan visits.
• Etc.

This requires that Shlink supports all relevant filters, but also that shlink-web-component allows to hide specific pieces of the UI based on its own restrictions system.

More context can be found in https://github.com/orgs/shlinkio/discussions/188

Use case

This would replace a feature added long ago to Shlink (API key restrictions), which was never the right place to handle it, but the only one available then.

With the Dashboard and its own backend, it is now possible to handle that kind of advanced logic here.