[node] Hook up map-wide "crossSourceCollisions" option, defaulting to true. [test] Pass "crossSourceCollisions" test option through test harness; enable cross-source-collisions tests on native.
[node] Hook up map-wide "crossSourceCollisions" option, defaulting to true. [test] Pass "crossSourceCollisions" test option through test harness; enable cross-source-collisions tests on native.