Update roi circle objects class

[HaleySchuhl]

Describe your changes
Updating pcv.roi.circle (and pcv.transform.create_color_card_mask since it uses pcv.roi.circle within the code) to use Objects class logic throughout

Type of update
Is this a:

• New feature or feature enhancement

Associated issues
#945

Additional context
Add any other context about the problem here.

For the reviewer
See this page for instructions on how to review the pull request.

• PR functionality reviewed in a Jupyter Notebook
• All tests pass
• Test coverage remains 100%
• Documentation tested
• New documentation pages added to plantcv/mkdocs.yml
• Changes to function input/output signatures added to updating.md
• Code reviewed
• PR approved

[codecov]

Codecov Report

❗ No coverage uploaded for pull request base (release-4.0@9583e77). Click here to learn what that means.
The diff coverage is 100.00%.

❗ Current head 42a8762 differs from pull request most recent head b9f0c53. Consider uploading reports for the commit b9f0c53 to get more accurate results

@@              Coverage Diff               @@
##             release-4.0     #993   +/-   ##
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  Coverage               ?   99.98%           
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  Files                  ?      161           
  Lines                  ?     6851           
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Flag	Coverage Δ
unittests	99.98% <100.00%> (?)

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
plantcv/plantcv/roi/roi_methods.py	100.00% <100.00%> (ø)
plantcv/plantcv/transform/color_correction.py	100.00% <100.00%> (ø)

[JorgeGtz]

Should we consider changing these to "plot"? I think that would be more beginner friendly.

[JorgeGtz]

Sorry for the delay!