feat: The ChannelList channels are not updated when a member joins a new channel

[dillionmegida]

Motivation The ChannelList component does not show the updated list of channels that a member belongs to when the member joins a new channel

In the video below, I'm using the ChannelList component on the left. And in the Browse Space modal, on clicking "+", I call the addMembers() method on the channel. But, the channel list is not updated until I refresh

https://user-images.githubusercontent.com/42855542/161017075-e3375c4c-7787-471e-9223-2278ec989250.mov

NB: Leaving a channel updates the list.

This Codesandbox explains it better. When you leave a channel, the channel leaves the channel list (although I just noticed too that after leaving an active channel, the activeChannel which the Channel component uses stays the same...you can check that)

However, joining a channel doesn't add the channel to the channel list automatically

Proposed solution Internally, I think the ChannelList component should handle the "MEMBER.ADDED" event, and update the list accordingly.

Acceptance Criteria

• [ ] joining a new channel updates the channel list