Handle HTTP chunking across multi-byte boundaries

When a response contains multi-byte UTF-8 characters that cross chunk
boundaries, appending the two halves to the intermediate string results
in two Unicode Replacement Characters being inserted instead of the two
halves being joined.

Set the response encoding to UTF-8 to ensure it buffers partial
characters between chunks.

Resolves #22

Co-authored-by: zyc9012 <zyc9012@gmail.com>

Author: Thomas Hurst

src/utils.ts

@@ -63,6 +63,7 @@ export function execute(
   return new Promise((resolve, reject) => {
     let timer: number;
     const req = https.get(url, (resp) => {
+      resp.setEncoding("utf8");
       let data = "";
 
       // A chunk of data has been recieved.