fix: fix node environment import

[gkatsev]

Fixes #59

[cjpillsbury]

The issue was obliquely build-related, but more specifically an issue with properties of an hls.js instance being referenced in a node runtime, including constants. By moving any of these references to within the corresponding method scopes, this obviates the problem occurring as a result of simply importing or requiring the @mux/videojs-kit in these environments.

[cjpillsbury]

Confirmed reproduction of issue in two ways:

• in a project with @mux/videojs-kit as a declared dependency
  • run node to start REPL
  • const videojs = require('@mux/videojs-kit); // throws error

    % node
    Welcome to Node.js v14.17.3.
    Type ".help" for more information.
    > const videojs = require('@mux/videojs-kit')
    Uncaught TypeError: Cannot read property 'NETWORK_ERROR' of undefined
    at Object.819 (/Users/cpillsbury/dev/tests/test-vjs-mk-nextjs/test-vjs-mk-nextjs/node_modules/@mux/videojs-kit/dist/index.js:77:4852)
    at Qe (/Users/cpillsbury/dev/tests/test-vjs-mk-nextjs/test-vjs-mk-nextjs/node_modules/@mux/videojs-kit/dist/index.js:78:1629)
    at Object.18 (/Users/cpillsbury/dev/tests/test-vjs-mk-nextjs/test-vjs-mk-nextjs/node_modules/@mux/videojs-kit/dist/index.js:77:4128)
    at Qe (/Users/cpillsbury/dev/tests/test-vjs-mk-nextjs/test-vjs-mk-nextjs/node_modules/@mux/videojs-kit/dist/index.js:78:1629)
    at /Users/cpillsbury/dev/tests/test-vjs-mk-nextjs/test-vjs-mk-nextjs/node_modules/@mux/videojs-kit/dist/index.js:78:2137
    at /Users/cpillsbury/dev/tests/test-vjs-mk-nextjs/test-vjs-mk-nextjs/node_modules/@mux/videojs-kit/dist/index.js:78:2155
    at /Users/cpillsbury/dev/tests/test-vjs-mk-nextjs/test-vjs-mk-nextjs/node_modules/@mux/videojs-kit/dist/index.js:1:83

• try importing statically in a nextjs app
  • run yarn create next-app to create an example app
  • go to directory and run yarn
  • yarn add @mux/videojs-kit
  • in the default example nextjs Home page, add import videojs from '@mux/videojs-kit';
  • run yarn dev
  • attempt to load the page, note the error

    Server Error TypeError: Cannot read property 'NETWORK_ERROR' of undefined

    This error happened while generating the page. Any console logs will be displayed in the terminal window.

Confirmed solution by:

• checking out branch referenced in this PR, installing and building the project
• yarn link the project
• yarn link @mux/videojs-kit in the aforementioned project(s)
• follow the same repro steps to confirm RTE no longer occurs.