Add recovery rate & mortality rate to the dashboard

Created by: djkher

Problem: Currently the dashboard displays the numbers (active, confirmed etc) but it doesn't show various rates such as recovery rate, mortality rate etc. These figures could be quite useful.

Solution: Add recovery and mortality rate to the dashboard. These can be calculated using simple division.

Recovery Rate = Total Recovered / Total Confirmed * 100 Mortality Rate = Total Deaths / Total Confirmed * 100

This could be at country level as well as state level.

Additionally we could also show these rates on a per day basis to understand the trend over a period of time. Although this might not be as useful as the overall recovery rate, it is worth considering