Elixir Chat Service

[joshleecreates]

Changes

Fix #1511. Creates an elixir-based chat service (Draft)

TODO

• [x] Update frontend to join channels based on the username
• [ ] Create an "Admin" frontend page to join user chats
• [ ] Add a proper UI for chat messages
• [x] Add an ecto/postgres integration for persisting chats from the genserver
• [ ] Add a custom macro to simplify telemetry generation in channels
• [x] Move to main docker-compose
• [x] Fix span representation for message producers/consumers
• [x] Ensure ecto spans are generated
• [ ] Move UI out of phoenix and remove phoenix page controller

Merge Requirements

For new features contributions please make sure you have completed the following essential items:

• [ ] CHANGELOG.md updated to document new feature additions
• [ ] Appropriate documentation updates in the docs
• [ ] Appropriate Helm chart updates in the helm-charts

Maintainers will not merge until the above have been completed. If you're unsure which docs need to be changed ping the @open-telemetry/demo-approvers.