Small Plot Viewer adjustments

[ManuelHentschel]

Addresses some issues that came up in the conversation of #678:

• Fixes the CSS used to change font colors
• Clarifies the description of two config entries

Also:

• Removes some unnecessary logging output
• Makes resizing the plot more "snappy" by not requesting an updated plot, while the previous request is still being handled

[renkun-ken]

LGTM. Works quite well.

[psobolewskiPhD]

I got the css override to work!
It was problem between chair and keyboard, as usual.
I didn't realize my file had to be also named styleOverwrites.css.
So I made a css file with a name that was more meaningful to me.
Now it works wonderfully, with the palette icon swapping working perfectly and my MacOS auto/light dark working beautifully.

styleOverwrites.css tweaked to not have strokes on the symbols and legend.
With the snappier resizing I don't mind that empty area, its just a few times pulled down past the edge (where the bottom panel starts) and made a super long plot that was annoying to resize back to normal.