Feature end live chat utterance - Send an utterance to the bot when the user disconnects from Amazon Connect live chat

[bobpskier]

Issue #, if available:
No Issue

Description of changes:

This pull request allows the lex-web-ui to send an utterance to the configured bot on completion of a live chat. The standard use case would be to kick off a post live chat survey by sending an utterance to the bot. On receipt of the utterance, the bot, for example AWS QnABot, could ask the user for feedback in the form of one or more survey questions. When the utterance is sent, several session attributes are set that provide Amazon Connect context for processing in bot: connect_initial_contact_id, connect_contact_id, and connect_participant_id. The handlers in the bot would typically store this information along with post live chat survey responses.

In addition, to sending the utterance, this pull request allows transcript entries to be redacted before sending to the agent during live chat startup. The use case here is that amazon connect supports reconnecting to an agent after live chat has completed. Without this change, the full transcript would be sent on the new request including any past survey results. Sometimes agents might be upset with seeing past poor survey responses. This feature allows a regex to be defined that when matched will redact those survey results.

By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.

[atjohns]

Hey, is the copy stuff on the release.sh file still necessary? I assume this came from when the build was not working correctly on Linux but that should have been cleaned up.

[bobpskier]

@atjohns Correct. The copy on the release.sh is not necessary for the pr.