feat: add Plaid transaction handling and async queue processing

- introduced new migration to add Cursor column to AccountMetadata.
- updated AppDbContext model snapshot to reflect changes in the database schema.
- implemented async queue processing with ChannelAsyncQueue and AsyncQueueHostedService.
- created Plaid transaction handlers for added, modified, and removed transactions.
- developed PlaidTransactionService and PlaidTransactionSyncer for syncing transactions.
- added SyncUpdatesProcessor to handle sync updates from Plaid.
- updated tests to accommodate changes in institution and account metadata handling.

src/FiscalOS.API/appsettings.Example.json

@@ -21,6 +21,7 @@
   },
   "PlaidClientOptions": {
     "ClientId": "ClientId",
-    "Secret": "Secret"
+    "Secret": "Secret",
+    "Webhook": "Webhook"
   }
 }