Typescript migration:

* Refactoring of scheduler and jobs to use promises.
* Add "failed" state for tasks.

package-lock.json

@@ -161,6 +161,15 @@
             "integrity": "sha512-uM4mnmsIIPK/yeO+42F2RQhGUIs39K2RFmugcJANppXe6J1nvH87PvzPZYpza7Xhhs8Yn9yIAVdLZ84z61+0xQ==",
             "dev": true
         },
+        "@types/node-cron": {
+            "version": "2.0.3",
+            "resolved": "https://registry.npmjs.org/@types/node-cron/-/node-cron-2.0.3.tgz",
+            "integrity": "sha512-gwBBGeY2XeYBLE0R01K9Sm2hvNcPGmoloL6aqthA3QmBB1GYXTHIJ42AGZL7bdXBRiwbRV8b6NB5iKpl20R3gw==",
+            "dev": true,
+            "requires": {
+                "@types/tz-offset": "*"
+            }
+        },
         "@types/nodemailer": {
             "version": "6.4.0",
             "resolved": "https://registry.npmjs.org/@types/nodemailer/-/nodemailer-6.4.0.tgz",
@@ -207,6 +216,12 @@
                 "@types/node": "*"
             }
         },
+        "@types/tz-offset": {
+            "version": "0.0.0",
+            "resolved": "https://registry.npmjs.org/@types/tz-offset/-/tz-offset-0.0.0.tgz",
+            "integrity": "sha512-XLD/llTSB6EBe3thkN+/I0L+yCTB6sjrcVovQdx2Cnl6N6bTzHmwe/J8mWnsXFgxLrj/emzdv8IR4evKYG2qxQ==",
+            "dev": true
+        },
         "Base64": {
             "version": "0.2.1",
             "resolved": "https://registry.npmjs.org/Base64/-/Base64-0.2.1.tgz",