Support for incremental edits

[Cubxity]

Add support for incremental edits, like the web application. This should improve the performance on huge documents.

[Myriad-Dreamin]

Feel free to borrow code from compiler/src/parser/mod.rs

[Myriad-Dreamin]

Updated official support: https://discord.com/channels/1054443721975922748/1152329229799804979
Related commit: typst/typst@5ef2842