Patch libh3 to include a document undefined check

[4nthonylin]

Address #117 and handles WebWorker as mentioned in #163. Note that this is a patch until #163 can be fully resolved.

[CLAassistant]

All committers have signed the CLA.

[nrabinowitz]

Thanks for submitting this - looks like a great workaround until we figure out how to upgrade emscripten.

[4nthonylin]

Just as a verification that webworker works:

// index.ts
const worker = new Worker(new URL('./worker.ts', import.meta.url), {type: "module"});
worker.onmessage = (e) => console.log(e);

worker.postMessage({type:"process_h3", value: [-120, 45]});

// worker.ts
import {latLngToCell} from "h3-js";

self.onmessage = (e) => {
    const data = e.data;

    if (data.type == "process_h3") {
        const [lng, lat] = data.value;
        self.postMessage(latLngToCell(lat, lng, 5));
    }
}

// console
MessageEvent {isTrusted: true, data: '8528ab77fffffff', origin: '', lastEventId: '', source: null}

[coveralls]

Pull Request Test Coverage Report for Build 3920825299

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 99.844%

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Totals
Change from base Build 3622927368:	0.0%
Covered Lines:	529
Relevant Lines:	529

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💛 - Coveralls

[nrabinowitz]

Thanks for contributing! I will try to push out a new release early this week.