🔨 Run once, graceful shutdown, db filename in env

- Refactored toISODateString function
- Added Db filename to env
- Added getOrDefault function for fetching envs, replaced LOG_LEVEL with getOrDefault
- Added script to run job once then exit
- Catch SIGINT signal and do a graceful shutdown

.env.example

@@ -4,6 +4,7 @@ ACTUAL_SYNC_ID=your-sync-id
 ACTUAL_SERVER_URL=http://your-server-url:5006
 ACTUAL_PASSWORD=your-password
 ACTUAL_ACCOUNT_IDS=your-account-id1,your-account-id2
+ACTUAL_DATA_DIR=.cache
 # Bank
 BANK_INITIAL_REFRESH_TOKEN=initial-valid-refresh-token
 BANK_OAUTH_CLIENT_ID=your-client-id
@@ -13,3 +14,4 @@ BANK_OAUTH_REDIRECT_URI=http://your-redirect-uri.com
 BANK_ACCOUNT_IDS=your-account-id1,your-account-id2
 # Configuration
 LOG_LEVEL=info# trace | error | warn | info | debug | trace
+DB_FILENAME=default