Rename the "status" identifier to "state" across the runtime entities (instance, token, work item, incident)

Follow-up to #3611306. Renames the overloaded status identifier to state across the four runtime entities (instance, token, work item, incident): base fields, STATE_* constants, getState()/setState()/getStateLabel(), the instance tokens [orchestra:state]/[orchestra:state-label], storage-schema indexes, Views field/filter configs, the admin filter/list, and the client API DTO/filter. Operation acks and HTTP status stay status. See #3611318.