Rewrite Example Event Loop

[cwfitzgerald]

Checklist

• Run cargo clippy.
• Run cargo clippy --target wasm32-unknown-unknown if applicable.
• Add change to CHANGELOG.md. See simple instructions inside file.

Connections
Closes #4627
Closes #4593

Description

This just completely redoes our event loop in the examples to:

• Be comprehensible
• Be correct

Testing

Manually

[PsichiX]

reminder for myself to test a fix with using canvas client size instead of inner size to set for canvas element size, to make canvas fill entire window area.
related conversation: https://discord.com/channels/676678179678715904/677286494033018924/1170896087020744835
notes to myself: also reproduce canvas setup of how Oxygengine does this, bc this precise combination of style worked in all and edge cases, also test scenario with canvas embedded in other elements.