Add the ability to create and export reports as PDF

[axpatito]

Hi everyone,

First of all @To-om this is my first Scala PR so pls be gentle :)

This PR implements the following process:

1. Migrates DB to generate a case_report model with a default empty report.
2. Adds an admin menu to modify the default report. (The report modal windows has an instance of the js case class, so all of those objects and attributes are available to use in the final report)
3. Adds a button on the UI when the case is closed to generate report.
4. The report button generates a pop up windows that reads the report generated in step 2 and renders it on screen.
5. jspdf (https://github.com/MrRio/jsPDF) is added as a dependency to render such content in a downloadable PDF.

ATM it is only possible to edit and use the default case_report (read below for next steps).

Also, tons of things can be done with jsPDF, so I was thinking on sharing a couple of templates. The base HTML template I'm using in the example is at https://gist.github.com/axpatito/082837b3053788218092ac47d56992f8

Screenshots:
Steps 1 and 2

Step 3

Step 4

Step 5

Why was it implemented like this?

The idea behind this PR is to be able to have and edit multiple report templates by admins, and give the analysts the posibility to choose one of those templates.

To do:

1. Document the javascript variables that are available to the report
2. Add to the admin form the possibility to create new case_report templates.
3. Add the ability to edit those templates.
4. Add a dropbox to the reports modal window to select the type of report.

[axpatito]

I did not see #678

I believe this PR implements the same functionality.

Closing it.

[crackytsi]

But i think only your pr supports pdf... :(

[nadouani]

I think we need a mix of them and some additions