feat: tce client additional tests

[atanmarko]

Description

Add additional tests for topos-tce-proxy and tce-client.

Fixes TP-731

PR Checklist:

• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have added or updated tests that comprehensively prove my change is effective or that my feature works

[codecov]

Codecov Report

Attention: 30 lines in your changes are missing coverage. Please review.

Comparison is base (745a57d) 60.67% compared to head (62a2bbb) 60.58%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #314      +/-   ##
==========================================
- Coverage   60.67%   60.58%   -0.10%     
==========================================
  Files         225      225              
  Lines       11967    12032      +65     
==========================================
+ Hits         7261     7289      +28     
- Misses       4706     4743      +37     

Files	Coverage Δ
crates/topos-test-sdk/src/tce/synchronizer.rs	100.00% <100.00%> (ø)
crates/topos-tce-proxy/tests/tce_tests.rs	48.68% <53.84%> (+3.85%)	⬆️

... and 9 files with indirect coverage changes

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