Add option to disable automatic canvas switching upon receiving search results.

This allows integrators to customize this behavior, e.g. by not
selecting the first, but another canvas via a custom saga.
The default is set to `true`, so there is no change in behavior
for integrators not setting this option.

src/config/settings.js

@@ -268,6 +268,7 @@ export default {
     highlightAllAnnotations: false, // Configure whether to display annotations on the canvas by default
     showLocalePicker: false, // Configure locale picker for multi-lingual metadata
     sideBarOpen: false, // Configure if the sidebar (and its content panel) is open by default
+    switchCanvasOnSearch: true, // Configure if Mirador should automatically switch to the canvas of the first search result
     panels: { // Configure which panels are visible in WindowSideBarButtons
       info: true,
       attribution: true,

src/state/sagas/windows.js

@@ -27,6 +27,7 @@ import {
   getElasticLayout,
   getCanvases,
   selectInfoResponses,
+  getWindowConfig,
 } from '../selectors';
 import { fetchManifests } from './iiif';
 
@@ -202,6 +203,10 @@ export function* updateVisibleCanvases({ windowId }) {
 
 /** @private */
 export function* setCanvasOfFirstSearchResult({ companionWindowId, windowId }) {
+  const { switchCanvasOnSearch } = yield select(getWindowConfig, { windowId });
+  if (!switchCanvasOnSearch) {
+    return;
+  }
   const selectedIds = yield select(getSelectedContentSearchAnnotationIds, {
     companionWindowId, windowId,
   });