Update default for add_id in plot methods

[rwood-97]

Summary

Updates the default for add_id argument in the plot methods in SheetDownloader.
This means if you don't have WFS ids in your metadata you won't get an error.

Checklist before assigning a reviewer (update as needed)

• Self-review code
• Ensure submission passes current tests
• Add tests
• Update relevant docs
• Update changelog

Reviewer checklist

Please add anything you want reviewers to specifically focus/comment on.

• Everything looks ok?

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Flag	Coverage Δ
unittests	77.66% <ø> (ø)

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Files with missing lines	Coverage Δ
mapreader/download/sheet_downloader.py	83.38% <ø> (ø)