[Slack] Improve Slack PostMessage with tagging channel and users

[kuroxx]

trafficstars

Issue Description

Current State

• In post message, we cannot tag name and channel now in Slack Component TASK_SEND_MESSAGE.

Why We Want to Change?

• The users will want to link the channel with the text e.g.

Proposed Change

1. Check if there is anyway to send message through the current status.

   • There may be a way that we can tag channel/user with some special way under the current status. If it does, please add this sample in the document.

2. If it cannot, need to check the Slack document to confirm how to modify the implementation of Slack Component to achieve the goal

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