Display projected voter APR on tracker

[helloicon]

The current experience for users optimise their p-reps selection is quite convoluted (necessitating handling bond figures, commission rates and p-rep power).

Could a new column be introduced to the p-rep list, giving a simple projected APR for new votes being added to the p-rep?
Could an API also be provided for these figures to allow products such as Hana to present a simple APR for P-reps moving forward?

[FidelVe]

this repo has code example on how to calculate APR for each validator
https://github.com/icon-community/icon-validator-earnings-calculator