Link dataconnect package and add invoice hub

Wire up the dataconnect-generated package for the web app and add a new `hub` field to invoice mutations and queries. Updates include: add package links in apps/web package and workspace config, adjust connector.yaml JavaScript SDK output/package paths, add `hub` to invoice create/update mutations and to invoice queries, remove many example dataconnect GraphQL files and the web README, and minor formatting/newline fixes (Makefile and several .gql files).

backend/dataconnect/connector/shiftRole/queries.gql

@@ -539,4 +539,4 @@ query getCompletedShiftsByBusinessId(
       #vendor { id companyName }
     }
   }
-}
+}