[CX] Support cluster-wide properties

Currently configurations are are maintained per node. We should add global configurations that are applied to all nodes - especially in the case that a new node is added to the cluster (e.g. max number of writable datasets).

• We need to store global parameters separately from node-specific ones
• Global and local parameters need to be merged before passing on to the JVM.
• Distinguish between global parameters that can be overridden by for a node and those that may not be overridden.
• Need to restart processes for most parameters (not for logging levels).