Update spectral wavelengths for CropReporter datasets

[nfahlgren]

Describe your changes
Updates the wavelengths assigned to spectral frames in CropReporter datasets to:

• 640, 550, 475nm are Red, Green, Blue
• 540, 710, 770nm are Anthocyanin, red-Edge, NIR

The existing wavelengths could cause some spectral indices to be computed with the incorrect frame: see #1373.

Type of update
Is this a: Bug fix

Associated issues
Closes #1373

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

Merging #1374 (3c47fd3) into main (21ab67f) will not change coverage.
The diff coverage is 100.00%.

Additional details and impacted files

@@            Coverage Diff            @@
##              main     #1374   +/-   ##
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  Coverage   100.00%   100.00%           
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  Files          156       156           
  Lines         6878      6878           
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  Hits          6878      6878           

Flag	Coverage Δ
unittests	100.00% <100.00%> (ø)

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

Files	Coverage Δ
...lantcv/plantcv/photosynthesis/read_cropreporter.py	100.00% <100.00%> (ø)