Add/restructure Media Analytics fields in XDM

[midomir]

What are the schemas that are affected by the issue

• advertising-timed-asset-reference.schema.json
• advertising.schema.json
• media-timed-asset-reference.schema.json
• media-timed-audio.schema.json [NEW]
• media-timed-chapter.schema.json
• media-timed-qoe.schema.json
• media-timed.schema.json

What are examples of products that are impacted by the issue

• Adobe Media Analytics

Internal JIRA issue: https://jira.corp.adobe.com/browse/VA-3365

High-level changes:

• addition of ad properites
• addition of video properties
• restructuring of audio fields to separate them from video fields
• move misplaced field (dropBeforeStart)