Normalize user data and implement user retrieval by ID

[jose250698]

Description

This pull request addresses two main tasks in the resolver module:

1. Normalizing user data: Previously, the resolver returned an empty array of users. This update implements the normalizeUser function to convert input user objects from different formats into a uniform schema. Properties from both userData1 and userData2 are mapped to this uniform schema.
2. Implementing user retrieval by ID: The getUserById function is now implemented to return a user by their ID from the correct data source. It checks the type of the ID to determine whether to search in userData1 or userData2. userData1 contains UUIDs (strings), while userData2 contains numerical IDs.

Changes Made

• Added implementation for normalizeUser function to convert input user objects into a uniform schema.
• Modified getUsers function to utilize the normalizeUser function for each user object before returning the final array of normalized users.
• Implemented getUserById function to return a user by their ID from the correct data source.
• Updated tests in resolver.test.ts to ensure correct functionality of getUserById for both UUIDs and numerical IDs, as well as to verify that the correct data source is used based on the ID type.

These changes enhance the resolver module's functionality and ensure consistency in user data representation and retrieval.