[iOS] Subscription to Hub methods is triggered only on Hub connection

[LukaszSadoch]

It is not possible to subscribe to methods after establishing a connection via Hub - and thus events are not returned from Webview to the app.

Calling subscribeToHubMethod does not generate any error, but no message is returned to the flutter application

[LukaszSadoch]

Suggestion of changes:

to file ios/Classes/SwiftR.swift:470 add:
connection.runJavaScript("addHandler('\(callbackID)', '\(name)', '\(method)')")

[AyonAB]

Okey, I haven't got time to test fully on ios after the recent changes. I applied your solution but its still not returning events for me. I think it needs more investigation.

[AyonAB]

Fixed this issue in latest pre release 0.1.0.