Backdate Maine TANF parameters

[hua7450]

Fixes #7160
Fixes #7212

Summary

Backdates Maine TANF parameters to include historical values from 2013 onwards, enabling accurate simulations for past years.

Changes

Resource Limit

• Added 1997-06-01: $2,000 (unchanged until P.L. 2023 Ch. 366 increased to $10,000)

Maximum Benefit

• Added historical values for family sizes 1-8:
  • 2013-11-01: Original values from SSA POMS
  • 2017-10-01: 20% increase (first increase in 16 years)
  • 2018-10-01: SSI COLA adjustment (+2.0%)
  • 2019-10-01: SSI COLA adjustment (+2.8%)
• Added SSA POMS reference for 2013 values
• Renamed each_additional.yaml → additional_person.yaml

Standard of Need

• Added historical values for family sizes 1-8 (2013-2019)
• Values maintain fixed differential from maximum benefit per LD 1475
• Renamed each_additional.yaml → additional_person.yaml

Other Parameters (backdated to 2013-11-01)

• child_care/amount.yaml
• earned_income/flat_deduction.yaml
• earned_income/percentage_disregard.yaml
• child_support_deduction.yaml

Tests

• Added 2018-01 test cases for size 3 household in both me_tanf_maximum_benefit.yaml and me_tanf_standard_of_need.yaml

References

• SSA POMS SI BOS00830.404 - Maine TANF (Effective 11/2013)
• 10-144 C.M.R. Chapter 331, Appendix Charts (Table 2)
• LD 1475 - Maintain differential since January 1, 2001

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 100.00%. Comparing base (dff5637) to head (10f2c5e).
⚠️ Report is 28 commits behind head on main.

Additional details and impacted files

@@             Coverage Diff              @@
##             main     #7213       +/-   ##
============================================
+ Coverage   76.71%   100.00%   +23.28%     
============================================
  Files        3665         2     -3663     
  Lines       52702        36    -52666     
  Branches      263         0      -263     
============================================
- Hits        40432        36    -40396     
+ Misses      12244         0    -12244     
+ Partials       26         0       -26     

Flag	Coverage Δ
unittests	100.00% <100.00%> (+23.28%)	⬆️

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