Fix #686 - LB_Map_Raw() counts refactor

[mattroumaya]

Overview

Fix #686
Replaces if_else() with case_when() to account for weirdness when NA values. NA values are introduced when filtering on domain data and joining to subject-level data.

Test Notes/Sample Code

Test that counts only contain 0 or 1:

# filter so join is missing some participants
lb <- clindata::rawplus_lb %>% filter(LB_GRADE %in% c(3, 4))

LB_Map_Raw(dfs = list(dfSUBJ = clindata::rawplus_subj, dfLB = lb))