Define an sftrack
new_sftrack(data, group_col, sf_col, time_col, error_col = NA)
data.frame with multi_burst column, geometry column, time_col (integer/POSIXct), and error column (optional)
column name of grouping info in `data`
column name of geometry info in `data`
column name of time info in `data`
column name of error info in `data`