Import Monday updates data as part of Monday migration

[cberger8]

Summary

Adds logic to the Monday migration script to import the updates data from Monday as private conversations.

Important Changes

src/scripts/MondayMigrate.js, src/scripts/MondayHelpers.js

• Added the updates migration logic

Testing

Steps to manually test updated functionality, if possible

• 1) Should correctly import updates data for each org into the Conversation collection with visibility marked private. The previous_conversation_uuid and next_conversation_uuid pointers should correctly chain, including if there were existing conversations (which should not be the case for our initial prod migration.)