[Plotters] It's possible to see the plotters available with various information on the plotter

Plotters view added to the platform. 
Contains:
- [x]  Plotters list and tables (and possibility to edit as admin)
- [x]  Plotter's view (public + user)
- [x]  Contains plotter's code and parameters + description
- [x]  Possibility to see reports containing the plotter (user + public)
- [x]  Added Plotters to statistics panel and activity stream user panel
- [x] Updated parts of the view and API
- [x] Added Plotters to drop down menus

See merge request !188