Move the trackingToken from option-detail.schema.json to decisionitem.schema.json

## What are the schemas that are affected by the issue
extensions/adobe/experience/decisioning/option-detail.schema.json
extensions/adobe/experience/decisioning/decisionitem.schema.json

Move the _xdm:trackingToken_ from option-detail.schema.json to decisionitem.schema.json as https://ns.adobe.com/experience/decisioning/decisionitem/trackingToken.

## What are examples of products that are impacted by the issue
This is for the upcoming new CBE feature which is not being used in current product.

Start by reading extensions/adobe/experience/decisioning/option-detail.schema.json and decisionitem.schema.json, then locate xdm:trackingToken in the first schema. Move it to decisionitem.schema.json under the specified decisionitem/trackingToken path, and confirm the property is no longer present in option-detail.schema.json.

Written by the indexing model from the issue text.