[ENH] Rename Intent Label to State label

[lakhoune]

Description:

We currently have an Intent Label field within the Incoming Message element. However, as this element now mainly represents a state, we propose renaming it to State Label for clarity and alignment with its actual function.

Details:

Current Implementation: The Incoming Message element contains an "Intent Label" field, originally designed to represent user intent. It now covers intent, context, and conversation state.

Reason for Renaming: "Intent Label" is misleading; renaming it to "State Label" aligns with its purpose and enhances system clarity.

Impact: This change benefits development, reducing confusion and improving user-friendliness.

Documentation Update: Update relevant documentation. Especially the fact that end users should use unique labels