Purpose of messages array in SessionInfo schema is undocumented

[sfnuser]

Problem description
SessionInfo schema in the spec contains messages object. The purpose of this object is undocumented

Expected behavior
This array object seems unnecessary and can be removed. If there is an purpose, it needs to be documented for implementation by vendors and use by developers.

[eric-murray]

Happy for this to be removed

[hdamker]

There were no objections to remove the array object raised within the QoD Call today.
@sfnuser please create the PR for it as agreed.
@camaraproject/quality-on-demand_maintainers if you are using this array and want to keep it, please describe your use case.