Add support for self signed certs with S3 in the MLOps pipeline

RHOAI now requires that all components and features support the use of self signed certificates that would be enabled in all cluster environments.

A spike was completed on this issue link here. A way to test if the pipeline is running successfully with the self signed certs would be to deploy a minio instance on the same cluster with the custom certificate and make test request, guide to minio.

In the MLops pipeline we use the kserve storage initialiser script. The v0.12 of the script should support self signed certs.

Acceptance criteria:

• A self signed cert can be passed as a parameter to the MLops pipeline and can be used for use with models that are fetched from a S3 bucket throughout the pipeline
• Update the go e2e-tests to support this, and document these steps
• Document this process and an optional step in the pipeline docs