cleanup: Remove definitions and move them to its relative places accordingly

- Move fs-definitions.go and break them into fs-datatypes.go, fs-bucket-acl.go
  and fs-utils.go
- Move api-definitions.go to api-response.go, where they should be.
- Move web-definitions to its related handlers.

pkg/probe/probe_test.go

@@ -13,6 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
 package probe_test
 
 import (