Move system settings configuration to Beam module

The settings were not propagated to the Skeleton and
were ignored by the Skeleton apps. This could cause
schedule commands not being execute due to "notOverlapping"
flags, which were written to the Redis correctly.

remp/remp#1292

config/system.php

@@ -0,0 +1,24 @@
+<?php
+
+$definition = env('COMMANDS_MEMORY_LIMITS');
+$limits = [];
+
+if (!empty($definition)) {
+    foreach (explode(',', $definition) as $commandLimit) {
+        $config = explode('::', $commandLimit);
+        if (count($config) !== 2 || empty($config[0]) || empty($config[1])) {
+            throw new \Exception('invalid format of COMMANDS_MEMORY_LIMITS entry; expected "command::limit", got "' . $commandLimit . '"');
+        }
+        $limits[$config[0]] = $config[1];
+    }
+}
+
+return [
+    'commands_memory_limits' => $limits,
+    'commands_overlapping_expires_at' => env('COMMANDS_OVERLAPPING_EXPIRES_AT', 15),
+    'commands' => [
+        'aggregate_article_views' => [
+            'default_step' => env('AGGREGATE_ARTICLE_VIEWS_DEFAULT_STEP'),
+        ],
+    ],
+];

src/BeamServiceProvider.php

@@ -84,6 +84,7 @@ public function boot()
             __DIR__ . '/../public/' => public_path('vendor/beam'),
             __DIR__ .'/../config/beam.php' => config_path('beam.php'),
             __DIR__ .'/../config/services.php' => config_path('services.remp.php'),
+            __DIR__ .'/../config/system.php' => config_path('system.php'),
         ], ['beam-assets', 'laravel-assets']
         );