Expose device property in ARTRealtime.h

[ben-xD]

According to RSH8 in the feature spec, Rest and Realtime should have a device method, but this doesn't exist in e.g. ARTRealtime.h Ably-cocoa. The method is defined in ARTRealtime.m though. To be consistent with ARTRest.h which exposes a property instead of a method, we could expose a property called device in ARTRealtime.h.

In ARTRealtime.m:

#if TARGET_OS_IOS
- (ARTLocalDevice *)device {
    return _internal.device;
}
#endif

We should make device property which provides ARTLocalDevice available from ARTRealtime.

┆Issue is synchronized with this Jira Uncategorised by Unito

[ben-xD]

Closing because this is already made available by @protocol ARTRealtimeProtocol <NSObject>:

#if TARGET_OS_IOS
@property (readonly) ARTLocalDevice *device;
#endif