[#482] Manual Authentication failing on test-agents/copilotstudio-webchat

[ceciliaavila]

Fixes #482
Fixes #450

Description

This PR fixes an issue in copilotstudioclient where only activities with text were supported.
The activity generated for the Office 365 consent card, for example, doesn't have a text; instead, the value of the clicked button is sent in the activity.value property.

{
  "activity": {
    "attachments": [],
    "channelData": {
      "clientActivityID": "9dfcaq9stpc",
      "postBack": true,
    },
    "channelId": "webchat",
    "from": {
      "id": "r_nhl5eooup9",
      "name": "",
      "role": "user"
    },
    "localTimestamp": "2025-08-01T16:42:33.718-03:00",
    "localTimezone": "America/Buenos_Aires",
    "locale": "en",
    "text": undefined,
    "type": "message",
    "value": {
       "action": "Allow"
     }
  },
}

Detailed Changes

• Created a new sendActivity function to post the activity to the Copilot Studio API.
• Updated askQuestionAsync function to call the new sendActivity method after creating the activity with the question's text.
• Replaced the call to askQuestionAsync with sendActivity in copilotStudioWebChat allowing activities with no text, like the one used in Office 365 consent cards.

Testing

This image shows the WebChat sample working with Manual Authentication. After pressing the "Allow" button, the Office 365 resource was successfully accessed, and an email was sent by the agent.

[rido-min]

LGTM