// 1. `subsys:target` -> request for config of a single subsystem and target pair.
// 2. `subsys:` -> request for config of a single subsystem and the default target.
// 3. `subsys` -> request for config of all targets for the given subsystem.
//
// This is a reporting API and config secrets are redacted in the response.
func (a adminAPIHandlers) GetConfigKVHandler(w http.ResponseWriter, r *http.Request) {
	ctx := r.Context()