[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

• [Proposal] allow rootBundle access from spawned isolates flutter/flutter#96895
• Streaming from assets flutter/flutter#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.

brendan-duncan/archive#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.