Support many Sig providers
requested to merge task/PSGS-777_remove_blocking_code_attempt_1 into task/PSGS-777_a_support_many_signature_providers
Support many Sig providers by making sign/create shared secre futures. Break node_jar into a core project and an extra project to reduce the surface area of core with a view to keeping it abstract and removing any blocking code. Begin the process of removing blocking code.