Refactor: controller: improve efficiency when deleting node state

Rename erase_status_xpath() to controld_delete_node_state() to follow current
naming practice.

Instead of passing it a node_state subsection name, pass a new enum value
indicating what to erase (resource history, transient node attributes, or
both). This allows us to improve the log messages further, as well as improving
efficiency when both need to be cleared.