Parameterize the rounding rules of indexed parameters in `policy_current_law.json`. This will likely require an update to the ParamTools package to handle rounding in the extrapolation of parameters.
Tax-Calculator should parameterize the rounding rules of indexed parameters in `policy_current_law.json`. There will probably need to be an update to the ParamTools package to handle rounding in the extrapolation of parameters. The need for rounding has been highlighted in PR #2652, where a new JSON file was created to help with the round-trip-reform test. With out that, all JSON files of past legislative reforms need to be updated to reflect rounding rules in years beyond those affected by the legislative change. Advantages of building in rounding rules: 1. Reduce time and errors in maintenance currently required to update rounded parameter values each year 2. Reduces the size of `policy_current_law.json` -- it would no longer need to include all values from the first to last known values (currently 2013-2022), but rather just values for any legislative changes 3. Allows for JSON files representing enacted laws to keep their integrity (no additional year values need to be a