refactor(loadmodule): refactor to use getmoduleloader

[kwonoj]

This PR refactors out loadModule logic into separate module https://github.com/kwonoj/emscripten-wasm-loader and removes most of preprocessor scripts via kwonoj/docker-hunspell-wasm#28, but provides interfaces for customizable asm module object.

[codecov]

Codecov Report

Merging #67 into master will not change coverage.
The diff coverage is 100%.

@@          Coverage Diff          @@
##           master    #67   +/-   ##
=====================================
  Coverage     100%   100%           
=====================================
  Files          13     10    -3     
  Lines         143    120   -23     
  Branches       21     14    -7     
=====================================
- Hits          143    120   -23

Impacted Files	Coverage Δ
src/util/logger.ts	100% <100%> (ø)	⬆️
src/loadModule.ts	100% <100%> (ø)	⬆️
src/index.ts	100% <100%> (ø)	⬆️
src/hunspellLoader.ts	100% <100%> (ø)	⬆️
src/mountDirectory.ts	100% <100%> (ø)	⬆️

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