Test for jobs in report.

Expand EmployersApplyingJobseekersByJobReportGenerator spec descriptions and code to test whether the applied-to jobs are also listed.
Fulfill expanded job report specs.

Fulfill expanded specs for EmployersApplyingJobseekersByJobReportGenerator. Its #generate_from now returns an instance of the new JobseekersAndJobsListReport report, which lists both jobseekers and the jobs to which they applied.
Add multi-job for jobseeker report spec.

Add spec checking whether EmployersApplyingJobseekersByJobReportGenerator reports on all of the jobs applied to by each jobseeker.
Fulfill multi-job for jobseeker report spec.

Fulfill spec confirming that EmployersApplyingJobseekersByJobReportGenerator reports on all of the jobs applied to by each jobseeker.

Refactor JobseekerAndJobsListReport (used by EmployersApplyingJobseekersByJobReportGenerator) to just group the results of the new JobseekerAndJobsReport class, as opposed to generating complete jobseeker reports manually.
Refactor duplication in JobseekerAndJobsReport.

Refactor JobseekerAndJobsReport to use existing reports instead of generating output on its own, reducing duplication.
Rename variables for accuracy.
Refactor for single responsibility.

Refactor JobseekerListReport to just consolidate output from the new JobseekerReport class.
Refactor for single responsibility in report.

Refactor JobseekerAndJobsReport to just use JobseekerReport instead of generating its own string.
Refactor specs for clarity.

Refactor the "should, for a jobseeker who applied to the given employer's jobs, list all of the employer's jobs to which they applied" spec for EmployersApplyingJobseekersByJobReportGenerator. Make it a spec for the JobseekerAndJobsReport used by that class, as that spec was only really testing that class anyway.
Restore placeholder for pending test.

Restore a placeholder for the "should, for a jobseeker who applied to the given employer's jobs, list all of the employer's jobs to which they applied" spec of EmployersApplyingJobseekersByJobReportGenerator.