12B: Let the queue that holds the notices say where they are

[nikolaystrikhar]

What: moves option_name() off Notices\Queue and Notices\Store as a public static and onto Notices\Contracts\Queue_Interface as an instance method.

Usage:

$option = Absorber::notices()->option_name();

foreach ( get_site_option( $option, [] ) as $notice ) {
    // Render them yourself.
}

Why this way:

The honest answer depends on which queue the site is running. A static answers for the default implementation whatever is actually bound, so on a site that rebound Queue_Interface to keep notices elsewhere, the snippet in docs/notices.md read an option nothing writes to.

On the contract rather than the default class. The docs invite a host to read the option and render the notices itself, so the object it holds has to be able to answer for itself. Store keeps the composition, since it is the class that owns the option.