Identify over-generous usage of pub in EE crate

Identify symbols that are pub, but are used only within EE crate and are considered internal, but are exposed anyway. Having (almost) everything as pub often increases time to develop new features just to avoid breaking changes. If there’s something that could be pub(crate), then make it pub(crate), or private. As part of this we can also identify types that are used in EE, but can be extracted to a separate crate for easier consumption, and could allow different versioning scheme.