Performance is not great for large block projects

[riknoll]

Our performance for large block programs is not great. We run into this issue all the time on livestream, but it's also reported by our users on the forum very often (and has been for many years).

Here's a sampling of forum posts:

https://forum.makecode.com/t/how-to-make-arcade-run-faster/20897

https://forum.makecode.com/t/im-working-on-a-game-for-school-but-its-lagging-alot/17562

https://forum.makecode.com/t/small-red-line-demo/19399/57

https://forum.makecode.com/t/what-is-your-biggest-project/19101

https://forum.makecode.com/t/the-phoenixs-quest-the-cloudy-climb-dlc-out-now/12915

https://forum.makecode.com/t/very-important-feature-for-makecode-editor/12009/6

https://forum.makecode.com/t/game-code-evaporated/18468

https://forum.makecode.com/t/announcement-makecode-arcade-mini-game-jam-2-submission-thread/14534/26

https://forum.makecode.com/t/personalnote-q-a/16345/3

https://forum.makecode.com/t/double-jumper-devlogs/17141/15

https://forum.makecode.com/t/announcement-makecode-help-desk/17507/5

[riknoll]

https://forum.makecode.com/t/dinocraft-the-most-in-depth-makecode-minecraft/21316/32

[srietkerk]

Not sure if we want to continue to add to this issue, but we have another report of a lost project. https://forum.makecode.com/t/help-with-pixel-art-end-math-issues/18809/74

[eanders-ms]

We don't know if the data loss was due to performance. Worth collecting data loss reports in a separate issue though.

[riknoll]

https://forum.makecode.com/t/makecode-is-too-slow/11996/6?u=richard

[riknoll]

https://forum.makecode.com/t/i-m-stepping-away-from-makecode/25809