Fix duplicate document problem in `CalexpQualityMonitor`

[danjampro]

• Use the original document as the document filter when updating calexp metrics in RawExposureCollection
• This avoids clashes when there are duplicate .fits and .fits.fz files.
• Also fix string representation of Document objects.

Closes #117 Closes #123

[codecov[bot]]

Codecov Report

Merging #124 (d86be95) into develop (db7d504) will decrease coverage by 0.26%. The diff coverage is n/a.

@@             Coverage Diff             @@
##           develop     #124      +/-   ##
===========================================
- Coverage    91.78%   91.51%   -0.27%     
===========================================
  Files           25       25              
  Lines         1777     1780       +3     
===========================================
- Hits          1631     1629       -2     
- Misses         146      151       +5     

Impacted Files	Coverage Δ
huntsman-drp/src/huntsman/drp/document.py	87.50% <0.00%> (-2.75%)	:arrow_down:
huntsman-drp/src/huntsman/drp/lsst/butler.py	91.66% <0.00%> (-0.84%)	:arrow_down:
huntsman-drp/src/huntsman/drp/services/calexp.py	90.27% <0.00%> (-0.39%)	:arrow_down:

---

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 db7d504...d86be95. Read the comment docs.