Add CSV export

[johnarban]

This PR adds CSV export for each dataset, as well as the ability to copy it to the clipboard so it can be pasted into CODAP or Google Sheets.

[patudom]

Thank you @johnarban, this is working well. I have a few suggestions that I think would help the user. We can discuss further if that would be helpful.

• I ended up with a bunch of download files with no way of figuring out what goes with which dataset other than comparing them one by one. Is it possible to use the dataset label as the filename instead of "download (xx)"?

• Use consistent labeling between displayed table data and downloaded csv file

• In a similar vein, I'm wondering if the table display should put the uncertainty in its own column to match the downloaded table format rather than using the "value (uncertainty)" notation.

• In general, I'm wondering if this table is the right format for displaying the data. No one is going to scroll through 500+ screens of numbers to get to the end of the table. What are we hoping students are going to learn from / do with the table display? If it's meant to be a view of the format of the data (kind of like how pandas shows the first ~10 and last ~10 rows of a dataframe), maybe we can just show the start and end of the table? But unless it's using up lots of additional memory to create the 500 pages of table display, maybe it's not hurting anything to leave it as is. 🤷‍♀️

• In both the table & downloaded file, we use "column density" which I don't think is terminology we use anywhere else. Do we want that to say "Quantity"? And is there a non-cumbersome way to indicate the unit in the column header label?

• Have you tried doing a copy/paste from the clipboard to codap, and was it successful? I tried copy/pasting to excel, and it gave me one giant column with all my comma-delimited content in each cell. If codap isn't smarter than that, then the copy to clipboard function won't be that useful, and I'm wondering if we want to have only the csv download button to simplify the layout.

• Is there a reason the Download Table text label is a different color than the Copy to clipboard label?

[patudom]

Thanks for making these updates, @johnarban!

I think we need to handle the copy/paste vs. the file download differently (and keep the downloaded file as comma separated). The copy/paste is now working well, but when I download the file and open it in Excel (which I think is likely what the user would do), it treats all the data as being in one column.

Also, for the non-aggregated data, the columns in the copy/paste and download are out of order.