Switch Data Sources from ITEM_ROUTED to ITEM_SENT

[jsutantio]

User Story
As a product manager and ReportStream team member, I would like my dashboard's data source to be the most accurate and reliable so that the resultant calculations and dashboards are less prone to error.

Description
This is a continuation of Create/ modify Azure event for more accurate OKR Metrics Dashboard #15766, which created a new Azure event that logs at the Send step – thus creating the ITEM_SENT event. This event will capture the same metadata as the current ITME_ROUTED event but will more accurately capture the status of the report.

The task is to switch the datasource from ITEM_ROUTED to ITEM_SENT within Power Query within Power BI. Another ticket (#16068) will take care of removing the duplicative results, that were caused by resubmissions or filtered out reports, which were accounted for in the ITEM_ROUTED event.

Acceptance Criteria

• Create new dashboard page that tallies volume of tests performed and sent to the STLT.
• Document changes in the documentation PowerPoint
• Publish updated OKR Metrics Dashboard