use intended lamports_per_signature for fee_structure

[tao-stones]

Problem

FeeStructure used in tests should be initialized with intended lamports_per_signature. Using FeeStructure::default() only works if lamports_per_signature == 0 or 5_000.

Summary of Changes

• Initialize FeeStructure with intended lamports_per_signature for tests

Fixes #

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (8f9d915) 81.8% compared to head (2bbfa3e) 81.7%.
Report is 2 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff            @@
##           master   #34845     +/-   ##
=========================================
- Coverage    81.8%    81.7%   -0.1%     
=========================================
  Files         825      825             
  Lines      223269   223270      +1     
=========================================
- Hits       182635   182623     -12     
- Misses      40634    40647     +13