feat: add postal code validation rule

[ns-vasilev]

No description provided.

[spacecode-github-bot]

	1 Warning
⚠️	Big PR - consider breaking it into smaller chunks

Generated by 🚫 Danger

[codecov]

Codecov Report

❌ Patch coverage is 99.86790% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 94.15%. Comparing base (9775b7d) to head (4c89c6a).
⚠️ Report is 3 commits behind head on main.
✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
...rCore/Classes/Rules/PostalCodeValidationRule.swift	99.22%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #90      +/-   ##
==========================================
+ Coverage   91.84%   94.15%   +2.31%     
==========================================
  Files          50       52       +2     
  Lines        1876     2633     +757     
==========================================
+ Hits         1723     2479     +756     
- Misses        153      154       +1     

Files with missing lines	Coverage Δ
...nitTests/Rules/PostalCodeValidationRuleTests.swift	100.00% <100.00%> (ø)
...rCore/Classes/Rules/PostalCodeValidationRule.swift	99.22% <99.22%> (ø)