Latency when launching/closing the Snap UI

[danroc]

There some latency when launching and closing the Bitcoin Snap UI.

Example:

Screen.Recording.2024-10-11.at.17.50.35.mov

We suspect that part of the issue comes from reading or updating Snap's storage state. In our test, we observed that fetching an empty state took ~4 ms, while a state containing around 20 cached transactions took ~200 ms.

We can help with proper tests if needed.