set_upstream_recursive: Recursively set upstream stations
In ECCC-MSC/Basin-Delineation: Finds upstream area and upstream stations

recursively sets all stations upstream of a target station

1	set_upstream_recursive(station, table, next_upstream, set_to = 1)

`station`	target station to set
`table`	a data.table describing upstream / downstream relationships between stations.
`next_upstream`	the next station upstream of the target station
`set_to`	toggle between setting upstream (1) or not upstream(0)

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M  <- initialize_matrix_from_stations(c('stn1', 'stn2', 'stn3', 'stn4'))
set_upstream('stn1', M, c('stn2', 'stn3'))
set_upstream_recursive('stn4', M, 'stn1')