Update `wazuh-states-vulnerabilities` index template

[AlexRuiz7]

Description

We have been asked to update the index template and mappings for the wazuh-states-vulnerabilities index with the following changes.

• Add 2 new fields to track the publication (published_at) and detection dates (detected_at) of the vulnerabilities.
• Remove the @timestamp field

As always, we need to update the mappings, update the events' generator, test the new index template and open a pull request in wazuh/wazuh to update the template.

[AlexRuiz7]

[AlexRuiz7]

We need to re-work this issues, as the fields detected_at and published_at should be inside the vulnerability class, not inside wazuh.

[AlexRuiz7]