added x-collaboration property to the message header.

Type of change

• Bug Fix
• Feature

Please provide link to gitlab issue or ADR(Architecture Decision Record)
storage#149 (closed)

Does this introduce a change in the core logic?

• [NO]

Does this introduce a breaking change?

• [NO]

What is the current behavior?

no "x-collaboration" property sent in the message header.

What is the new/expected behavior?

"x-collaboration" property returned in the message header.