Report: Portfolios with reviewer

My story
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As an institution admin I want to see quickly how many portfolio authors (don't) have a reviewer on a weekly basis so that I can report over these numbers, track the development, and intervene if necessary.

How
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General information for the report
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* Normal reporting capabilities are retained, e.g. that when a person is selected, reports are only shown for them where applicable reports are available, select data range, configuration selected on the configuration screen, columns are sortable (unless where it does not make sense due to the data, which should be mentioned).
* When 'Personal information' is mentioned, this means:
  * First name, last name, display / preferred name, username, student ID.
  * Preferred name is ticked per default but can be unticked and other fields selected instead.
* Each column (but personal information and email) receives help text icon.
* Each column is sortable (unless where it does not make sense due to the data, which should be mentioned).

Report-specific
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This report is for the number of portfolio authors with and without the role of 'Reviewer' set for a portfolio that they copied / that was copied from a template.

Weekly snapshot report created each Monday at 1:30 (TBD) for the previous week.

* Pie chart
* Line graph
* Tabular report

**Pie chart (snapshot overview)**

* Displays number of portfolio authors with and without current reviewer as at Sunday at 23:59 for the previous week
* Display includes the number of portfolio authors and the percentage
* In configuration be able to select which templates (via multi-select) shall be displayed and make that a sticky selection.

**Line graph snapshot (report over time)**

* Display number of portfolio authors with a current reviewer as at Sunday at 23:59 for the previous week. Variations that happen during the week are ignored.
* Data points are on a monthly basis and can be clicked to see the results (both number and percentage). Variations during the week do not matter.
* Same template(s) selected as for pie chart graph

**Tabular report columns**

* Week, i.e. Monday through Sunday of the previous week, represented by 'w.c. Monday date' (w.c. = 'week commencing') as we have in another report
  * Number of portfolio authors that have a current reviewer on Sunday at 23:59
  * Number of portfolio authors that don't have a current reviewer on Sunday at 23:59
* Regular date selector.
* On configuration screen filter for which portfolios to display via a multi-selector that is sticky.