Add multiple pages to an existing bot service Facebook channel

**Related command**

Currently the bot service only provides the [Azure-CLI command](https://docs.microsoft.com/en-us/cli/azure/bot/facebook?view=azure-cli-latest#az-bot-facebook-create) to create a single page Facebook Channel connection. There's no command for creating a multiple page Facebook Channel connection, or command for adding multiple pages to an existing bot service Facebook channel.

There's already a similar issue reported issue #7564 . But it still remains unresolved so far.

**Is your feature request related to a problem? Please describe.**

Help customer raise this feature request.

The customer's organization requires to automate the addition of Pages since every time the client subscribes to the chatbot they want their page to automatically get assessed by the bot instead of making them wait for 24 hours and having our developers do the entire process manually.


**Describe the solution you'd like**

Provide a command for adding multiple Page IDs and Access Tokens to an existing bot service Facebook channel, instead of doing it manually.

**Describe alternatives you've considered**

Any other automation method could also be good.