Support Electron's renderer process

[kwonoj]

• fix(preprocessor): support electron with node context docker-hunspell-wasm#27 or upstream PR gets merged
• ModuleLoader supplies ENVIRONMENT (https://kripken.github.io/emscripten-site/docs/api_reference/module.html?highlight=environment#overriding-execution-environment) to NODE for applicable case (for binaryEndpoint case too) fix(constructmodule): inject environment #8
• supply locateFile for non-binary-endpoint case if needed

[kwonoj]

Now this is mostly solved, just need bump emscripten with latest binaryen clang compatible target.