Add the `pathf` feature to mingling dependency and invoke
`analyze_and_build_type_mapping` during the build script.

Reorganize internal module visibility from `mod + pub use` to
direct `pub mod`.

Extract duplicate `MockCollect` implementations into a reusable
`MockProgramCollect` type. Conditionally require `Serialize` on the
`Groupped` trait when the `general_renderer` feature is enabled.