Ability to disable/enable assumptions regarding sideEffectfulness for node_modules and project code independently

[vicapow]

[vicapow]

I believe this was behavior prior to 1.12.1. Until this can be supported, we have to maintain our own custom patches to Fusion

[mlmorg]

This would be a good idea but the priority seems low at this point. If this occurs for more folks, we can re-prioritize. We may try to get this done before end of H1 2019.