c7d555e585
Replaced `ScaffoldingConverter` with a set of `FfiValue*` classes. The differences are: * The new classes better match other `uniffi-bindgen-gecko-js` names, and also use familiar UniFFI terms like `Lift` and `Lower`. * Object handles are now freed if there's an error. * The new classes store the FFI value internal rather than defining an `IntermediateType` associated type. * Moved header files into `mozilla/uniffi/` and removed the `UniFFI` prefix from the filename. This avoids weird filenames like `UniFFIFfiValue.h` Differential Revision: https://phabricator.services.mozilla.com/D240696