Incorporation of BSS Dataset

[keatonwilson]

This PR generates a draft version of incorporating the peak bed stress (bss) data into the app. Generally, the buildout focused on a few key areas:

1. Pre-processing of the bss data to map vector direction into quadrants (NW, SW, SE, NE) that were then rasterized
2. Generating vector arrows on a leaflet map - this is done on the fly by creating poly lines corresponding to magnitude and direction. It currently filters for the top 500 vectors for each year. We will probably want to change this - it's pretty dense right now.

I also cleaned up a few misc. items - explicit name spacing of some functions and the annoying dropdown of the data input widget inside the card (it now overflows correctly).

@jessicaguo I'll start identifying more specific tasks now that we're through some of the big stuff. Thanks in advance for the review!

[keatonwilson]

Thanks for figuring this out! Unfortunately on my end, I cannot load the bss data without the whole app shutting down on me, and no error message to let me know why. Nevermind, I just needed to run a renv::restore. I can see the map now, woohoo! I especially appreciate the drop-down menu fix.

One small concern about the color legend for both categorical datasets - it seems that there will be some NA or "other" output resulting from rasterizing the matrix. How will we differentiate between land and NA?

@jessicaguo Woohoo! Glad to see that it worked after restore. Yeah - I've been thinking about that too. I tried to get rid of as many NAs as I could in the pre-processing (you can see some of those steps in the pre-processing updates). But we'll have to think about it more specifically for each data set (and what NAs actually mean). Would you main opening an issue for this so we can keep track of it?

Otherwise, am I good to merge?

[jessicaguo]

Just tacked on the stratification legend. Will do on issue, and okay to merge!

[jessicaguo]

Closes Issue #18