Explore page unwieldy with 50k results

[ehinman]

Describe the bug

The explore page is extremely slow to load and the map was nearly unusable with lots of data on it. The plotly plots were also slow to load, with the two-parameter plot taking ~5 minutes to load. At about 2 minutes, Chrome told me the page was unresponsive, but I waited it out and it eventually displayed.

To Reproduce

Steps to reproduce the behavior:

1. Downloaded WI data from 10-25-2022 to 08-25-2023 in app

2. Reordered orgs, flagged, applied filter, censored data, harmonization and summation, etc.

3. Opened explore page, grouped by TADA.ComparableDataIdentifier and selected Temperature, water DEG C and PH standard units to be displayed on the map/plots for all sites

4. Wait

Additional context

I designed the tab flow to be 1. group characteristics, 2. pick characteristics, 3. map and plot, 4. filter sites and re-plot. This might not be the best flow, but it's hard to pick the right one. Are users more interested in viewing groups by site (with site being the first filter), or do they want to use the groups to pick sites to view and then further refine (use characteristic group to filter sites)? This might be better answered from an efficiency standpoint though. One thing that might speed it up is to not have the default site selection for plotting be "All sites". That could be slowing things down. I will say that I find plotly nearly unusable with medium datasets and larger (>50k points). It is very slow to load, slow to update to user interactivity, etc. There might be optimization I'm not aware of though.

Reminders for TADA contributors addressing this issue

New features should include all of the following work:

• Create the function/code.

• Document all code using comments to describe what is does.

• Create tests in tests folder.

• Create help file using roxygen2 above code.

• Create working examples in help file (via roxygen2).

• Add to appropriate vignette (or create new one).