[Document] Potentially misleading inline comment for PollWorkflowTaskQueueResponse

[taonic]

What are you really trying to do?

To clearly understand the scope of the workflow history returned in PollWorkflowTaskQueueResponse.

Describe the issue

At the moment, the inline comment is stated as below:

The history for this workflow, which will either be complete or partial. Partial histories
are sent to workers who have signaled that they are using a sticky queue when completing
a workflow task.

However, the term "complete" can be misleading as for long event history, this will only return the first page and rely on next_page_token for subsequent fetches.