DOM-Offloading to IndexDB

[X4AES]

Hi, I've ported DSH to Rust, Julia and Nim to experiment with Rust being most successful. However one session ended up quite long and led to extreme lag within the web session. Any click is delayed by 10 seconds or more. The UI becomes unusable.

This is because all data is kept in memory. I've 64GB RAM and yet it's becoming unresponsive for various reasons, but mainyl because all data is mutating constantly the entire DOM while constantly increasing the size. Streaming into and from IndexDB is the most logical choice given this would make the UI much more snappy.