Load OJIP data on-demand

[nfahlgren]

Describe your changes
This PR adds new classes for OJIP dark and light measurements, PSD and PSL, respectively. Unlike CHL and CLR data, PSD and PSL load the OJIP data from file each time. We don't expect users to access the PSD and PSL data directly, rather the YII and NPQ analysis functions will instead.

ps = pcv.photosynthesis.read_cropreporter("PSII_HDR_020321_WT_TOP_1.INF")
print(ps.psd)
# PSD(filepath='PSII_PSD_020321_WT_TOP_1.DAT')
psd = ps.psd.load()

Type of update
Is this a: Work in progress

Associated issues
#1926

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• PR functionality reviewed in a Jupyter Notebook
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[deepsource-io]

DeepSource Code Review

We reviewed changes in 308298b...8b67e89 on this pull request. Below is the summary for the review, and you can see the individual issues we found as inline review comments.

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PR Report Card

Overall Grade

Security   Reliability   Complexity   Hygiene   Coverage

Code Review Summary

Analyzer	Status	Updated (UTC)	Details
Python		May 28, 2026 9:59p.m.	Review ↗
Code coverage		May 28, 2026 9:59p.m.	Review ↗

Code Coverage Summary

Language	Line Coverage (New Code)	Line Coverage (Overall)
Aggregate	100% [✓ above threshold]	99.9% [▼ down 0.1% from main]
Python	100% [✓ above threshold]	99.9% [▼ down 0.1% from main]

➟ Additional coverage metrics may have been reported. See full coverage report ↗

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[joshqsumner]

Looks good. Leaving a note here that we should simplify the test_read_cropreporter function once these edits are done

[joshqsumner]

I like the changes to the tests, should be easier to parse errors and expand to next sub-classes.