Update dashboard statistics charts

Currently, on the "dashboard" page, the data for the statistics charts are mocked and hard-coded.

Maybe divide in two parts ?

Suggestions for statistics of INSYLVA search tool usage:

• number of user log-in
• number of user sign-in
• total number of user by roles
• number of basic searches
• number of advanced searches
• most searched words
• most selected fields
• most active group
• group with most users
• group with most sources

Suggestions for statistics of INSYLVA server / admin side:

• number of containers active
• number of containers refreshed
• number of containers crashed
• real-time CPU usage
• real-time temperature

To-do:

• Identify needed statistics
• Find a way to store needed statistics
• Correctly display said statistics on page load
  • let user choose by day/week/month/year/all time
  • Remove 3 dots menu (or make it work)
  • Choose graph colors