XDM support for Player State Tracking fields

## What are the schemas that are affected by the issue
* media-timed-asset-view-details.schema.json
* player-state.schema.json [NEW]

## What are examples of products that are impacted by the issue
* Adobe Media Analytics

Internal JIRA issue: https://jira.corp.adobe.com/browse/VA-3232

High-level changes:
* addition of player state tracking fields (fullScreen, mute, closeCaption, pictureInPicture, inFocus)

Start by reviewing media-timed-asset-view-details.schema.json and the existing schema conventions before defining player-state.schema.json. Add the player state tracking fields fullScreen, mute, closeCaption, pictureInPicture, and inFocus to the affected schemas, with the new schema represented consistently with the XDM model.

Written by the indexing model from the issue text.