Provide more specific information in error/warning messages

[martinholmer]

This pull request is an attempt to provide more information about which element of a non-scalar policy parameter is being discussed in an error or warning message. There are three kinds of non-scalar parameters: some are indexed by MARS, others are indexed by EIC, and a few are indexed by itemized-deduction-type. The need for more information in the messages was pointed out by @hdoupe in the discussion of TaxBrain pull request 641.

Using the revised code in this pull request, the error and warning messages look like this:

tax-calculator$ cat ref.json
{"policy": {
    "_II_rt2": {"2020": [0.0]},
    "_II_brk2": {"2020": [[10000, 10000, 10000, 10000, 10000]]},
    "_STD_Dep": {"2020": [200]}
}}

tax-calculator$ tc cps.csv 2020 --reform ref.json
ERROR: 2020 _II_brk2_1 value 10000.0 < min value 19954.96 for _II_brk1_1
ERROR: 2020 _II_brk2_3 value 10000.0 < min value 14284.11 for _II_brk1_3
ERROR: 2020 _II_brk2_4 value 10000.0 < min value 19954.96 for _II_brk1_4
ERROR: 2021 _II_brk2_1 value 10233.0 < min value 20419.91 for _II_brk1_1
ERROR: 2021 _II_brk2_3 value 10233.0 < min value 14616.93 for _II_brk1_3
ERROR: 2021 _II_brk2_4 value 10233.0 < min value 20419.91 for _II_brk1_4
ERROR: 2022 _II_brk2_1 value 10470.41 < min value 20893.65 for _II_brk1_1
ERROR: 2022 _II_brk2_3 value 10470.41 < min value 14956.04 for _II_brk1_3
ERROR: 2022 _II_brk2_4 value 10470.41 < min value 20893.65 for _II_brk1_4
ERROR: 2023 _II_brk2_1 value 10714.37 < min value 21380.47 for _II_brk1_1
ERROR: 2023 _II_brk2_3 value 10714.37 < min value 15304.52 for _II_brk1_3
ERROR: 2023 _II_brk2_4 value 10714.37 < min value 21380.47 for _II_brk1_4
ERROR: 2024 _II_brk2_1 value 10964.01 < min value 21878.63 for _II_brk1_1
ERROR: 2024 _II_brk2_3 value 10964.01 < min value 15661.12 for _II_brk1_3
ERROR: 2024 _II_brk2_4 value 10964.01 < min value 21878.63 for _II_brk1_4
ERROR: 2025 _II_brk2_1 value 11220.57 < min value 22390.59 for _II_brk1_1
ERROR: 2025 _II_brk2_3 value 11220.57 < min value 16027.59 for _II_brk1_3
ERROR: 2025 _II_brk2_4 value 11220.57 < min value 22390.59 for _II_brk1_4
ERROR: 2026 _II_brk2_1 value 11484.25 < min value 22916.77 for _II_brk1_1
ERROR: 2026 _II_brk2_3 value 11484.25 < min value 16404.24 for _II_brk1_3
ERROR: 2026 _II_brk2_4 value 11484.25 < min value 22916.77 for _II_brk1_4
WARNING: 2020 _STD_Dep value 200.0 < min value 1123.47
WARNING: 2021 _STD_Dep value 204.66 < min value 1149.65
WARNING: 2022 _STD_Dep value 209.41 < min value 1176.32
WARNING: 2023 _STD_Dep value 214.29 < min value 1203.73
WARNING: 2024 _STD_Dep value 219.28 < min value 1231.78
WARNING: 2025 _STD_Dep value 224.41 < min value 1260.6
WARNING: 2026 _STD_Dep value 229.68 < min value 1290.22
USAGE: tc --help