Update Arc video player implementation to support third-party embeds (e.g. NPR)

As an organization, we would be empowered to use our connection to NPR and its content to the fullest degree and would be able to bring that content to our audience in a seamless way.

Without this change, our audience will not be able to access NPR videos embedded in NPR stories.

Some NPR stories have embedded videos that we can't easily embed because of the way the data is formatted from the NPR CDS API.

The Arc video player component has the capability of supporting embedded videos that aren't hosted in Arc's Video Center, but the current implementation in OPB's codebase will have to be adjusted to allow for this, as it only allows for videos that are stored in Video Center at the moment.

We currently use Arc's powaBoot.js library and we would need to switch to Arc's powa.js library in order to support third-party embeds such as the ones that NPR provides. See this Arc documentation for details.

• Arc provides a CloudFront URL for each organization (https://< CloudFront hash >.cloudfront.net/prod/powa.js).

• If the powa.js script is particularly large, we would probably want to replace the powaBoot.js script and use powa.js instead to save on load times for the user.

• We would need to write code that used the .m3u8 manifest file that's sent from NPR to access the video file programmatically and load it into the player while maintaining the current capability of loading videos directly from Video Center