home: Show org icon in app bar (Inbox, Channels, Direct messages)

[chrisbobbe]

A user reports wanting to see more quickly which org is focused in the UI:

#mobile > feedback: goro muta @ 💬

What I'm dissatisfied with is that it's not immediately clear which of your multiple accounts you're currently logged into. (Both the old version and the upcoming Flutter beta version)

I have the Inbox displayed when I log in (default), but in groups where I don't post often, there are often no threads displayed when I log in (when I launch the app), so I don't know which account I'm in. And it's only when I click on the feed or channel tab that I find out which account I was in.

This is quite inconvenient.

In the Figma design for the "Inbox", "Channels", and "Direct messages" pages, the org icon is shown in the app bar:

• https://www.figma.com/design/1JTNtYo9memgW7vV6d0ygq/Zulip-Mobile?node-id=5966-178689&m=dev
• https://www.figma.com/design/1JTNtYo9memgW7vV6d0ygq/Zulip-Mobile?node-id=6205-25955&m=dev
• https://www.figma.com/design/1JTNtYo9memgW7vV6d0ygq/Zulip-Mobile?node-id=5956-115859&m=dev

Inbox	Channels	Direct messages

We should follow that. Then as followups, the icon can respond to tap and swipe gestures:

• One-tap access to list of accounts from home #1162
• Swipe to access different accounts #1211

Related issues

• One-tap access to list of accounts from home #1162
• Swipe to access different accounts #1211
• Show current organization's name and icon atop main menu #1037