Add support for jobs & queueables, migrations

- Create migration directives & migrators
- Modify Cache classes to support array manipulation
- Create Redis unit and RedisCache implementation
- Create Queueable base class and Queue class that uses Cache backend

src/service/Canon.ts

@@ -1,5 +1,6 @@
 import {Canonical} from './Canonical'
 import {Singleton} from '../di'
+import {Maybe} from '../util'
 
 /**
  * Error throw when a duplicate canonical key is registered.
@@ -46,6 +47,17 @@ export class Canon {
         return this.resources[key] as Canonical<T>
     }
 
+    /**
+     * Get a canonical item from a fully-qualified canonical name.
+     * This is just a quality-of-life wrapper around `this.resource(...).get(...)`.
+     * @param key
+     */
+    getFromFullyQualified(key: string): Maybe<any> {
+        const [namespace, ...parts] = key.split('::')
+        const unqualified = parts.join('::')
+        return this.resource(namespace).get(unqualified)
+    }
+
     /**
      * Register a canonical resource.
      * @param {Canonical} unit