This is largely a leftover from the Backbone.View days and makes less
sense now that the UI is componentized.
Ideally we don't want to call commands on the "views themselves, instead
we should be working on the the models and let the "views" update
themselves automatically.
Also, given that the `jid` attribute on the chat views might change,
especially when rendered declaratively in other frameworks like React,
a view might not be available at times where we previously might have
expected it to be (since it's been repurposed for a different JID).
More work on making bottom panel sub-components declarative
- Handle auto-completion in the converse-muc-message-form element
- Make message limit indicator a component
- Rename template