Move `adder-toolbar` -> `AdderToolbar`

src/annotator/adder.js

 import { render } from 'preact';
 
-import AdderToolbar from './components/adder-toolbar';
+import AdderToolbar from './components/AdderToolbar';
 import { isTouchDevice } from '../shared/user-agent';
 import { createShadowRoot } from './util/shadow-root';
 

src/annotator/test/adder-test.js

@@ -32,7 +32,7 @@ function revertOffsetElement(el) {
 
 // nb. These tests currently cover the `AdderToolbar` Preact component as well
 // as the `Adder` container. The tests for `AdderToolbar` should be moved into
-// `adder-toolbar-test.js`.
+// `AdderToolbar-test.js`.
 describe('Adder', () => {
   let adderCtrl;
   let adderCallbacks;