test(katana-provider): add tests for contract classes + fix provider state impl

[kariy]

Main purpose of this PR is to add tests for testing reading contract classes from both latest and historical state providers.

This PR also updates/fixes some bugs found in the providers' state impls thanks to the newly added tests.

[codecov-commenter]

Codecov Report

Attention: 2 lines in your changes are missing coverage. Please review.

Comparison is base (ce4f395) 64.27% compared to head (960a847) 64.63%.

Files	Patch %	Lines
...ana/storage/provider/src/providers/fork/backend.rs	66.66%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1333      +/-   ##
==========================================
+ Coverage   64.27%   64.63%   +0.35%     
==========================================
  Files         229      229              
  Lines       19713    19722       +9     
==========================================
+ Hits        12671    12747      +76     
+ Misses       7042     6975      -67     

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