UI: We should provide users with way to change the paths for service while adding new nodes to the cluster.

Currently, the users cannot change the paths of various services like data path, index path or analytics path when adding the nodes to the cluster using Admin UI. The users can only set the path during the initial cluster setup. To set paths for individual nodes, the user has to first use couchbase-cli node-init to initialize the node and then add using the Admin UI or couchbase-cli. We should add functionality to let users change the various paths to the node while adding the node to the cluster just like we allow the user to select the different services that the node will have.