Viz cleanup

[infotroph]

Description

• Namespace fixes
• Roxygen tweaks
• Biggest change: renamed plot.netcdf to plot_netcdf. Technically this is a breaking change, but I believe in practice it's only called from the web workflow and I've updated it to match.

Motivation and Context

I'm clearing out my Git stashes and pushing all the bits of code cleanup that I did while working on other things and then put aside to maintain focus in the original PRs. Expect more like this as the week goes on.

Review Time Estimate

• Immediately
• Within one week
• When possible

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My change requires a change to the documentation.
• I have updated the CHANGELOG.md.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.