Standardize entanglement risk report

[brooke-l-hawkins-noaa]

Create more standardized output for fishing effort and entanglement risk.

• improve monthly maps by generating them for a) pre-RAMP, b) post-RAMP, and c) difference; for fishing effort
• add aggregation from gridded summary into a single number into pipeline, and report median and IQR instead of just one number

There's also a design question inherent in this task: Should we be automating the full report, or just the first steps related to fishing effort?

For example, I could add maps and summary statistics for ii) whale presence, and iii) entanglement risk, but the whale presence portion belongs squarely to Heather. We could include her in the repository, but I suspect she has her own repo to organize that work. One compromise would be to add her code, with a clear credit (her name as author at top of the file), and the only whale-related step in our repository would be to choose the whale gridded risk files (e.g. with file.choose() function).