feat: include pre-built JS files that are browser-loadable and CDN-ready

[bguiz]

Problem

• when I would like to use the Hedera SDK in a browser application
• but I'm required to use a Javascript build tool/ bundler before being able to use it in my application
• when I'm simply trialling the SDK, or building a POC, I would prefer to simply import the entire SDK from a CDN URL

Solution

• add an npm run script within this repo that builds/ bundles the SDK
• its output should functional within a browser application
  • e.g. in UMD format, compiled into a single file, and comes in "full" format as well as minified+source mapped format
• place the output in a dist directory within the repo
• add a CI/CD step that performs
  • the npm run script which performs such a build upon each release
  • syncs the built file onto CDNs such as jsdeliver

Alternatives

Refs

• discussion - https://swirldslabs.slack.com/archives/C0453UVBR42/p1712460885992259
• related issue: Bundle issue in browser environment with esbuild #2173
• related issue: Modernize and improve bundle size #1719
• developer friction point: https://stackoverflow.com/q/78271342/194982
• illustration of problem: https://github.com/InternetOfPeers/hedera-sdk-js-standalone-library-example
• illustration of problem: https://github.com/hedera-dev/hedera-code-snippets/blob/feat/dapp-hedera-sdk/dapp-hedera-sdk/