Slack Integration: include attributes of original post

[#1]

In the Slack integration that enables posting an update to a project, issue or task - include details about the original post. This should include:

• original author name
• date/time of post (in Slack)
• ideally a link to the original post

Currently this only shows info for the WF user who added it as an update - and makes it look like they wrote the update which is inaccurate.