[ACTION] Slack - usability updates

[malexanderlim]

Usability Improvements

1. $.summary should return names, instead of IDs - this is user-facing and should read as such:
   Successfully sent a message to channel ID C074G5N4BHD to Successfully sent a message to @michael

2. It looks like reply-broadcasts has been deprecated - should be thread-broadcasts now:
   https://api.slack.com/events/message/reply_broadcast#markdown
   https://api.slack.com/events/message/thread_broadcast

For send-message:
2. Instead of Public Channel and Private Channel, we should just have one prop Channels and list both public and private channels.
3. Create new optional prop, Reply to Thread which unfurls the Message Timestamp prop.

For sending messages in general:
4. Can we change the name of send-custom-message to send-message-advanced "Send Message (Advanced) - this makes more sense to me than a "Custom Message."
5. I can't figure out how to successfully structure the data to pass in Metadata Event Type and Metadata Event Payload, but I can do this from the API. Can we make this more clear on what should be passed in here?

Nesting of additionalProps under a single additionalProp for better usability

6. Create new optional prop, Customize Bot Settings and which should reveal the following additionalProps under it:

• Bot Username
• Icon (emoji)
• Icon (image url)

7. Create new optional prop, Add Message Metadata which should unfurl Metadata Event Type, Metadata Event Payload props.

8. Create new optional prop, Configure Unfurl Settings which should unfurl Unfurl Links, Unfurl Media props.

[vunguyenhung]

Hello everyone, I have tested this PR and there're some test cases failed or needed improvement.

Please check the test report below for more information
https://vunguyenhung.notion.site/ACTION-Slack-usability-updates-7d8b25cf87f54062b1762258cb51c32b

[vunguyenhung]

Hello everyone, I have tested this PR and there're some test cases failed or needed improvement.

Please check the test report below for more information
https://vunguyenhung.notion.site/ACTION-Slack-usability-updates-7d8b25cf87f54062b1762258cb51c32b

[vunguyenhung]

Hi everyone, all test cases are passed! Ready for release!

Test report
https://vunguyenhung.notion.site/ACTION-Slack-usability-updates-7d8b25cf87f54062b1762258cb51c32b