Modify link to sample data in Dashboards section and references to opensearch dashboards

[Tostti]

Description

When accessing the Dashboards section, if no dashboards are created, it shows a default message. This message suggests adding sample data and provides a link to do so.
That link points to Opensearch's sample data section, which we removed from the application. We need to modify it so it redirects to Wazuh's sample data section.

We should also modify the OpenSearch Dashboards for Wazuh dashboard