[Improvment] At first boot unpack the data in isolate to avoid unresponsive UI

[CaptainDario]

Basically what the title says, would be great to unpack the data from the assets in an isolate to avoid dropped frames / frozen UI / un responsive app. For this, the rootbundle needs to be accessible from an isolate because currently copying the whole assets to the isolate to unpack it takes a very long time.

Realted issues

• https://github.com/flutter/flutter/issues/96895
• https://github.com/flutter/flutter/issues/73322

[CaptainDario]

Correction: copying the data to the isolate is really fast, there are serious performance problems introduced in the archive package after v3.3.2.

https://github.com/brendan-duncan/archive/issues/294

[CaptainDario]

Data is unpacked in an isolate now. It still would be nice not to copy the data to the isolate and rather open it their directly.