refactor(transaction): introduce TransactionInputError for user input validation

- Added TransactionInputError class to handle user-facing resolution failures in transaction steps.
- Updated path resolution and expression validation functions to throw TransactionInputError for invalid inputs.
- Enhanced RPC API error handling to return bad input responses for TransactionInputError instances.

Author: docloulou

packages/orm/src/client/index.ts

@@ -32,6 +32,7 @@ export {
     $first,
     $filter,
     $map,
+    TransactionInputError,
 } from './transaction';
 export type {
     StepRef,