Agent Registration Fails Due to 201 Status Code

[vikman90]

Parent Issue: #241

Description

When an agent successfully registers, the API responds with status code 201. However, the agent incorrectly interprets this status as an error:

Registration error: 201.
wazuh-agent registration failed

Steps to Reproduce

1. Register an agent against a properly configured API.
2. Observe the registration process logs.
3. Note that despite a 201 response, the agent reports the registration as failed.

Expected Behavior

The agent should treat 201 as a success code for registration, not as an error.

Proposal

Update the agent to correctly handle a 201 status code as a successful registration response.