Add benchmark for generated munlib file sizes

[Wodann]

• claim this issue (assign yourself or comment below)
• setup repository on your local machine and make sure all tests pass (cargo test)
• read our contributing guidelines
• add a benchmark that compiles the Mun packages in examples/ and records the *.munlib file sizes
• add a ci job that runs benchmarks on main and reports a warning if files sizes have increased.
• (BONUS) Figure out a way to plot a graph, either in Rust or on our website to show the history of *.munlib file sizes.
• start a Pull Request. Set description to closes #419. If this is your first PR, welcome 🎉 😄

Depends On

• Add benchmark for generated munlib file sizes #419

[alexandrasp]

@Wodann, I will start with this one. Could you assign it to me?

[Wodann]

Great choice, thank you!