🎉 Allow syncing multiple accounts at once

- By defining multiple account keys in the .env, will fetch from all and upload to correct account
- If transaction id is 0, will not be marked as cleared
- Added accountKey to Transaction interface

httpRequests/sparebank1API.http

@@ -51,6 +51,8 @@ GET {{bankingBaseUrl}}/accounts
 Authorization: Bearer {{ACCESS_TOKEN}}
 
 ### Fetch all transactions of specific days (inclusive)
-GET {{bankingBaseUrl}}/transactions?accountKey={{brukskontoAccountKey}}&fromDate=2025-01-20&toDate=2025-01-22
+GET {{bankingBaseUrl}}/transactions?accountKey={{accountKey1}}&accountKey={{accountKey2}}&
+    fromDate=2025-01-20&
+    toDate=2025-01-24
 Authorization: Bearer {{ACCESS_TOKEN}}
 Accept: application/vnd.sparebank1.v1+json; charset=utf-8