overhaul to get the quality back together

fixed:

• [Safari only] remove global state object to resolve "not found" error
• [Firefox only] re-write parse RegExps to not rely on /s

internal:

• changed from Jinja2 with a custom build script to Elventy as build orchestrator
• pull flag images, Sentry and Line-Awesome from npm instead of bundling them in the repo
• add reporting of ScoreSaber data to Sentry to diagnose remaining parse errors