Instead of only exposing a User to slash commands we now also expose the
ChatName object that the User object is retrieved from. This is
necessary for GitLab Chatops as we need for example the user ID of the
chat user.
Fix https://gitlab.com/gitlab-org/gitlab-ce/issues/27070
Deprecate "chat commands" in favor of "slash commands"
We looked for things like:
- `slash commmand`
- `slash_command`
- `slash-command`
- `SlashCommand`
Mark Chao