Index name pattern not present in the error message

[astefan]

During a REST IT test on a secured cluster, in case the index pattern is an inexistent index, the error message itself is stripped of the index being searched for resulting in a message of the form {"error":{"root_cause":[{"type":"verification_exception","reason":"Found 1 problem\nline -1:-1: Unknown index [*,-*]"}] for a search like /inexistent/_eql/search whereas the expected is to have the index pattern in the error messge itself.

[elasticmachine]

Pinging @elastic/es-security (:Security/Security)

[elasticmachine]

Pinging @elastic/es-ql (:Query Languages/EQL)

[astefan]

As mentioned in a different GH issue touching the same area as this issue, I understand the meaning of *, -* and the reasons behind Security using it. I will follow up with a PR to have the original pattern in the error message provided by EQL. Assigned myself this issue.