Added support for all lifecycle events on iOS and Android

[bartonip]

I've added support for all lifecycle events on iOS and Android and the plugin is sending up the exact lifecycle transition from each platform in case granular control of events by platform is required.

[ajinasokan]

Could you tell me what is the use case of these additional events?

Also this will be a breaking change since PR seem to remove the existing foreground and background events. That is undesirable. The best I can think of is an additional getter platformEvents that streams all these.

[yasinarik]

Actually, this PR should be accepted since it gives an extended detection of the app lifecycle. It solves the issue a have opened: #6. Until the merge, I have to use the package pointing the forked repo of @bartonip.

There are plenty of use cases for catching these additional lifecycle states. For example:

-in a finance application: to prevent exposing any sensitive information),
-a timer based trivia game: to prevent users to send the game to background or app switcher.

Apart from that, yes, even though it is more comprehensive, the new enum naming is different in this PR that causes a breaking change.

[Hwan-seok]

This is great but seems android's onStart does not map to anything so it is reported as unknown.
According to the following lifecycle image, it might be reported as willEnterForeground

[ajinasokan]

This PR is now almost 10 months old 🥲

Since I want to make this change non breaking, I will fork this PR and add these events into a different stream and a different factory constructor on the Widget to use these.