Re-implement improvements to str_length check

[cosmicBboy]

This PR provides an alternative implementation to #2177 which is backwards compatible, while providing an exact_value for specifying exact string length values

[codecov]

Codecov Report

❌ Patch coverage is 63.63636% with 16 lines in your changes missing coverage. Please review.
✅ Project coverage is 83.78%. Comparing base (776eea4) to head (31402d9).
⚠️ Report is 2 commits behind head on main.

Files with missing lines	Patch %	Lines
pandera/backends/pyspark/builtin_checks.py	0.00%	16 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2198      +/-   ##
==========================================
- Coverage   83.87%   83.78%   -0.10%     
==========================================
  Files         137      137              
  Lines       10617    10636      +19     
==========================================
+ Hits         8905     8911       +6     
- Misses       1712     1725      +13     

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