Update logic for Native vs. Hls.js engines

[erikpena]

• We favor engines that allow for HLS in players within browsers
• If no native but browser supports Hls.js, use Hls.js
• If browser is can't handle native or hls.js, then playback will fail

[erikpena]

Using the changes in this PR, I ran through a set of manual tests against different platforms -> browsers. Here are the results—

| Platform | Browser    | Result         |
==========================================
| iOS      | Safari     | Native, played |
| iOS      | Chrome     | It played      |
| iOS      | Firefox    | It played      |
| iOS      | DuckDuckGo | It played      |
| Android  | Chrome     | It played      |
| Android  | Samsung    | It played      |
| Android  | Firefox    | It played      |
| Android  | DuckDuckGo | It played      |
| Android  | Opera      | It played      |
| Android  | Edge       | It played      |
| macOS    | Safari     | Native, played |
| macOS    | Chrome     | Hls.js, played |
| macOS    | Firefox    | Hls.js, played |
| Windows  | Edge       | Hls.js, played |
| Windows  | Chrome     | Hls.js, played |
| Windows  | Firefox    | Hls.js, played |

"It played" means that it worked but I had no DevTools to confirm what code path it took (native or hls.js)

[dylanjha]

closes #39