Describe the feature

Apps that import yaegicore, such as the documentation website, end up including every symbol in a lot of packages (especially icons), in addition to the base size of yaegi itself. That substantially increases the binary size, impacting load times on web. We should use https://github.com/Zxilly/go-size-analyzer to figure out what packages are contributing the most and what we can cut. If we could figure out some way to include fewer icons in yaegicore, that would help a lot.

Relevant code