feat: emit WAMessageStubType.GROUP_CHANGE_DESCRIPTION event

[arthursimas1]

this PR implements the WAMessageStubType.GROUP_CHANGE_DESCRIPTION event which is triggered by a description update of a group. it also works for community descriptions.

[whiskeysockets-bot]

Thanks for your contribution.

The next step is to wait for review and approval to merge it to main repository

The community can help reacting with a thumb up (:thumbsup:) for approval and rocket (:rocket:) for who has tested it.

To test this PR you can run the following command below:

# NPM
npm install @whiskeysockets/baileys@arthursimas1/Baileys#feature/emit-group-description
# YARN v2
yarn add @whiskeysockets/baileys@arthursimas1/Baileys#feature/emit-group-description

[Salientekill]

I was looking for this