Optimize online CoAP decoder

[twyatt]

#42 integrated a CoAP decoder webapp that is deployed to GitHub Pages.

It utlilizes browserDevelopmentWebpack Gradle task for building the static pages for the webapp. Unfortunately the development builds are extremely bloated. Attempts to use the production tasks for generating web distributions failed (unable to call Kotlin from JavaScript).

Testing with the js(IR) compiler worked (for calling Kotlin from JavaScript) but did not work with the current version of Okio (which is not compiled with IR compiler).

In the future we should either:

1. Check if js(LEGACY) has fixes that properly allow calling Kotlin from JavaScript
2. Switch to js(IR) when Okio supports it (preferred)

More details can be found at https://stackoverflow.com/a/65680291/196486.

[twyatt]

We switched to IR in #79, should find time to test if the production webpack builds work (and if so, switch to deploying with them).