cleanup/feat: solidify Structure handling and usage throughout

[atlas0fd00m]

unify the User Struct and Vstruct interfaces: some form of cohesion and a good direction for end-user modules to make use of custom structures

make the VivWorkspace actually use the structures for more than marking static memory as a struct. make function analysis and function api's use structs better and more.

this is a bit of a high lift, but worthwhile