[ECO-4234] Updates Push Example to include Channels

[umair-ably]

Updated.Push.Example.mov

• Users can now subscribe to 2 predefined example channels to test Channels based push.
• Updated the UX to be more in line with Ably's Design System.

[maratal]

Looks really cool, thanks @umair-ably
A couple of suggestions:

• "Subscribe" buttons might want to have more friendly captions.
• "Close" icon on a subscription button should be in a different state (for unsubscribe).
• After subscription fails it should show an error. I think it's better to introduce a dedicated control for this (a TextView in the bottom for example), where all the diagnostics info is displayed. Alerts are kinda headache in the SwiftUI (you can do this in a different PR later).

[maratal]

I think sending by clientId also should be added to this example. It's the same code, but you set clientId instead of deviceId in the recipient dictionary.

[umair-ably]

I think sending by clientId also should be added to this example. It's the same code, but you set clientId instead of deviceId in the recipient dictionary.

The readme already covers this use-case using the Push Inspector. When running on a single device/simulator, push via client or device behave the same - you only really notice the difference if you had several simulators running. Could be something worth adding as a future improvement, but not a pressing improvement for the key things this example showcases imo

[umair-ably]

Looks really cool, thanks @umair-ably A couple of suggestions:

• "Subscribe" buttons might want to have more friendly captions.
• "Close" icon on a subscription button should be in a different state (for unsubscribe).
• After subscription fails it should show an error. I think it's better to introduce a dedicated control for this (a TextView in the bottom for example), where all the diagnostics info is displayed. Alerts are kinda headache in the SwiftUI (you can do this in a different PR later).

• I left the Subscribe captions more "code-based" as that is the names the readme walks the user through when setting up the channel capabilities in the dashboard
• Good spot! I've updated this.
• Agreed, error handling in general is pretty naff in this. Will look to update in a future PR.

[jamienewcomb]

Hey team , unless there is anything generally wrong this is a vast improvement on what we had before so lets work on this idea and get it landed.

any further enhancements can be implemented as required

cc @lawrence-forooghian @umair-ably @maratal

[maratal]

I've created an issue for the error handling #1888

[maratal]

LGTM