use new napi functions to allocate returned memory

[julianhille]

According to this blog electron 21 has introduced
caged memory and native modules need refactoring to continue using ArrayBuffers and other off heap memory.
Actually muhammara might or might not run in electron > 21 as it just crashes when pointers / memory is not sandboxed.

We need to find a way to be backwards compatible to node and to older electron versions.

how to:
https://www.electronjs.org/blog/v8-memory-cage#i-want-to-refactor-a-node-native-module-to-support-electron-21-how-do-i-do-that

References:
https://www.electronjs.org/de/blog/electron-21-0#v8-memory-cage-enabled
https://www.electronjs.org/blog/v8-memory-cage
https://docs.google.com/document/d/1HSap8-J3HcrZvT7-5NsbYWcjfc0BVoops5TDHZNsnko/edit