Add additional tracking and offer proposition attributes to the Experience Event - Proposition Interactions field group

## What are the schemas that are affected by the issue
https://github.com/adobe/xdm/blob/master/extensions/adobe/experience/decisioning/option-detail.schema.json

Parent Object node: _experience.decisioning.propositions.items
Add:
selectionId: String
selectionType: String
trackingToken: String

## What are examples of products that are impacted by the issue
These are the additional optional attributes for new reporting capability. There is no impact to the existing application.

Open extensions/adobe/experience/decisioning/option-detail.schema.json and locate the _experience.decisioning.propositions.items node. Add the three optional string attributes named in the issue: selectionId, selectionType, and trackingToken. Done means the schema contains these attributes under the specified parent without changing existing application behavior.

Written by the indexing model from the issue text.