Make MaxCut a u32

[nikki-aranya]

We currently have a MaxCut type that aliases to usize which we shouldn't be sending over the network due to platform incompatibilities, as well as it currently not being public. Instead, let's make it a u32 and refactor our APIs. Let's also double check the places where we use a max_cut but don't use the type (for example in Address).

[jdygert-spok]

Maybe make it a newtype wrapper for a little more type safety and encapsulation