Prepares the statement and runs the external saga_cmd executable
run_cmd(saga_cmd, saga_config, lib, tool_cmd, args, verbose)
list, output from `processx::run()`
character, name of the saga_cmd executable or alias.
character, path to the saga configuration "ini" file.
character, name of the selected library.
character, name of the selected tool.
named list of tool options, such as list(DEM = "mygrid.tif", RADIUS = 3).
logical, whether to show all saga_cmd messages on the R console.