Adjust epsilon for ticket quality tests

[masih]

Depending on the CPU architecture, the ticket quality tests fail due to differences in exact fraction calculation.

Update the tests to:

• always assert delta of 1e-15 for fraction
• assert epsilon error of 1e-3 when fraction is non-zero (otherwise relative error can't be calculated)
• assert exact equality when fraction is zero.

This is an slight overkill in assertion for the benefit of documenting intent in an executable test.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 79.27%. Comparing base (bcdd23d) to head (63abe8f).
Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #594      +/-   ##
==========================================
- Coverage   79.61%   79.27%   -0.35%     
==========================================
  Files          52       52              
  Lines        4617     4617              
==========================================
- Hits         3676     3660      -16     
- Misses        586      593       +7     
- Partials      355      364       +9     

see 7 files with indirect coverage changes