Add transition and step dimensions to orchestration reporting events

## What are the schemas that are affected by the issue
- `extensions/adobe/experience/campaign/orchestration/reportingevent.schema.json`
- `extensions/adobe/experience/campaign/orchestration/reportingexternalevent.schema.json`

## What are examples of products that are impacted by the issue
Adobe Campaign

## Description
For a more specific reporting, add two new dimensions: transition and step.
Internal JIRA issue: `ACSS-9938`.

Start by reading extensions/adobe/experience/campaign/orchestration/reportingevent.schema.json and reportingexternalevent.schema.json, then compare their existing reporting dimensions. The work is complete when both schemas represent the transition and step dimensions needed for more specific Adobe Campaign reporting, with the schema structure remaining consistent.

Written by the indexing model from the issue text.