add h2r_aggregate_occurence() function?

[zackarno]

@twesigye10 and @Dmutai

I added some functions to aggregate settlement data to hexagon by pct here. It doesn't use the {survey} or {srvyr} packages so it's faster.

Note:

1. It doesn't have the slick ability to take the concatenated select multiple column name that {butter} has .... but this could easily be added. This is not so important for the WASH analysis since we are not batch analyzing as many cols, but might be nice if it's adopted for H2R. I would not prioritize adding this at the moment.
2. Currently "SL" and "NC" are treated as NA and subset from analysis, but you can modify this and or make an argument so it can be adjusted depending on needs

TODO:

Recommend making a function like h2r_hex_aggregate_occurence() . This would juts return a binary T/F column indicating whether a certain value was reported in any settlement within the hexagon. This would be useful for climatic shocks?

@twesigye10 - do you think you could give this a try? it's basically just a spatial join to the grid and then some {dplyr} manipulation/summarizing