Is it possible to require approval before a page edit is made live?

Unfortunately, WP Core does not support this type of workflow. Plugin requests are considered off-topic here because plugin functionality can change and some plugins don’t last, but I think it would be helpful to the community (and OP) to know that Oasis Workflow satisfies these basic requirements. The downside is, the editors who can’t publish end up being able to edit all post types. So, if you have a more complex workflow where you want some editors to edit only specific post types, you’re out of luck with that plugin and will have to code a solution yourself.

WP Core will be tackling workflow (at long last) in phase 3 or 4 of Gutenberg development, currently set for early 2020. Hopefully enough of the community will be vocal about this type of requirement, which is common to many CMSs and has long been difficult to shoehorn in.