Generate CSRs directly for more tests

[mdekstrand]

This changes test generation to focus on generating CSRs directly in more cases.

[codecov]

Codecov Report

Merging #22 (a8780b8) into main (2e10cd0) will increase coverage by 0.17%.
The diff coverage is 90.00%.

@@            Coverage Diff             @@
##             main      #22      +/-   ##
==========================================
+ Coverage   94.56%   94.74%   +0.17%     
==========================================
  Files          19       19              
  Lines        1085     1103      +18     
==========================================
+ Hits         1026     1045      +19     
+ Misses         59       58       -1     

Impacted Files	Coverage Δ
csr/kernels/mkl/handle.py	91.66% <66.66%> (-0.81%)	⬇️
csr/test_utils.py	94.73% <92.30%> (+4.41%)	⬆️
csr/csr.py	95.34% <100.00%> (+0.01%)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 2e10cd0...a8780b8. Read the comment docs.