feat: Automate admin notice when it is required by an extension

[josephfusco]

As a WPGraphQL extension author, I would like to have my WPGraphQL extension be suggested if the plugin that it depends on is active. This behavior would be similar to how WPGraphQL for ACF is suggested when both WPGraphQL and ACF are active.

wp-graphql/src/Admin/AdminNotices.php

Lines 35 to 54 in d3542ef

	register_graphql_admin_notice(
	'wpgraphql-acf-announcement',
	[
	'type' => 'info',
	'message' => __( 'You are using WPGraphQL and Advanced Custom Fields. Have you seen the new <a href="https://acf.wpgraphql.com/" target="_blank" rel="nofollow">WPGraphQL for ACF</a>?', 'wp-graphql' ),
	'is_dismissable' => true,
	'conditions' => static function () {
	if ( ! class_exists( 'ACF' ) ) {
	return false;
	}
	// Bail if new version of WPGraphQL for ACF is active.
	if ( class_exists( 'WPGraphQLAcf' ) ) {
	return false;
	}
	return true;
	},
	]
	);

[justlevine]

Two things to keep in mind:

• the possibility of multiple competing extensions for the same dependency ( per Extensions Directory Submission Criteria & Validation #3205 )
• the possibility of bad actors listing unnecessary requirements to trigger the recommendation.

Both can be mitigated ( e.g. using the Requires Plugins header, linking to a filtered view if more than 1 plugin in the directory matches the same plugin) if care is taken when implementing.