feat: gains function calculate_match_success_rate()

[jacobvjk]

add function that replicates the logic of calculating the match success rate for a loan book, following the implementation here: https://github.com/RMI-PACTA/workflow.aggregate.loanbooks/blob/main/run_match_success_rate.R

• this follows the calculation as described here https://rmi-pacta.github.io/r2dii.match/articles/matching-coverage.html
• borderline cases need to be handled
• NAs need to be handled
• needs an an option to remove specific loan_ids, to ensure that misclassified loans can be excluded

AB#10187

[jacobvjk]

relates to RMI-PACTA/r2dii.plot#563

[jacobvjk]

priority because the refactor of P4S depends on this