Add support for typing notifications when editing messages

[timabbott]

Description of feature missing from another Zulip client

Zulip 10.0 added support for typing notifications when editing messages. The terminal client will want to implement this eventually.

See #33024 and https://chat.zulip.org/#narrow/channel/378-api-design/topic/typing.20notifications.20for.20editing.20messages/near/2072444 for the API design.

When was this feature first available in Zulip?

If you know:

• Zulip version: 10.0.
• Zulip feature level: 351

[theofficialvedantjoshi]

@timabbott I would like to work on this feature. How do I get started ?