Stop breaking at first cron event when looping over events to run/delete

The `wp cron event run` and `wp cron event delete` commands are almost identical, and they both have the problem of doing a `break` after the first matching hook is found. However, you may have scheduled multiple events for the same hook but with different cron arguments associated with it, for example:

```php
wp_schedule_single_event( time(), 'computer_numbers', array( 1, 1 ) );
wp_schedule_single_event( time(), 'computer_numbers', array( 2, 2 ) );
```

Only one of these will get run via WP-CLI currently. So we should instead looping over them all.

So for `wp cron event run`, something like this change:

```diff
diff --git a/php/commands/cron.php b/php/commands/cron.php
index db4e07d..bc67221 100644
--- a/php/commands/cron.php
+++ b/php/commands/cron.php@@ -116,7 +117,7 @@ class Cron_Event_Command extends WP_CLI_Command {
        }

        /**
-    * Run the next scheduled cron event for the given hook.
+  * Run the next scheduled cron event(s) for the given hook.
         *
         * ## OPTIONS
         *
@@ -126,24 +127,27 @@ class Cron_Event_Command extends WP_CLI_Command {
        public function run( $args, $assoc_args ) {

                $hook   = $args[0];
-           $result = false;
                $events = self::get_cron_events();

                if ( is_wp_error( $events ) ) {
                        WP_CLI::error( $events );
                }

+         $found = 0;
                foreach ( $events as $id => $event ) {
-                   if ( $event->hook == $hook ) {
+                 if ( $event->hook === $hook ) {
                                $result = self::run_event( $event );
-                           break;
+                         if ( $result ) {
+                                 WP_CLI::success( sprintf( "Successfully executed the cron event '%s'", $hook ) );
+                         } else {
+                                 WP_CLI::error( sprintf( "Failed to the execute the cron event '%s'", $hook ) );
+                         }
+                         $found += 1;
                        }
                }

-           if ( $result ) {
-                   WP_CLI::success( sprintf( "Successfully executed the cron event '%s'", $hook ) );
-           } else {
-                   WP_CLI::error( sprintf( "Failed to the execute the cron event '%s'", $hook ) );
+         if ( 0 === $found ) {
+                 WP_CLI::warning( sprintf( "Cron event '%s' not found", $hook ) );
                }

        }
```