Pc report service

[pconrad]

In this PR, we add a new service (at this point, still not accessible to the end user), along with tests for that service.

The service can be used as the basis to produce a new job (in a future PR) that produces an instructor report.

Overview

This PR adds the entity and repository classes for two new database tables: Report and ReportLine.

A Report is a snapshot of activity about a particular commons. The Report row takes a snapshot of the Commons level information. A ReportLine takes a snapshot of a particular UserCommons in that Commons.

The ReportService has a createReport method that creates a new row in the Report table, and a ReportLine row for each UserCommon row. Together, this is a complete snapshot of the state of the game at the time the report was generated.

Future Work

This PR only creates the database tables, and the Report Service. Future PRs will create:

• a job to invoke the service (backend)
• swagger endpoints to launch the job (backend)
• swagger endpoints to retrieve the report rows (backend)
• a frontend component to launch the job from the Admin => Jobs page.
• a frontend feature where Admins can view reports (and possibly download them).

[jingpeng7527]

LGTM