Use IDestroyable instead of IDisposable

For consistency within our project

src/utils/IDestroyable.ts

@@ -14,6 +14,6 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-export interface IDisposable {
-    dispose(): void;
+export interface IDestroyable {
+    destroy(): void;
 }