Fix missing await for asynchronous method calls in the integration tests

The `Page.evaluate()` and `Mouse.click()` APIs in Puppeteer both return
a promise; see https://pptr.dev/api/puppeteer.page.evaluate and
https://pptr.dev/api/puppeteer.mouse.click, and should therefore be
awaited before proceeding in tests to make sure that the test's behavior
is deterministic and avoid intermittent failures.

The following command was used to find potential places to fix:
`grep -nEr "[^await|return] page\." test/integration/*`

Author: timvandermeij

test/integration/freetext_editor_spec.mjs

@@ -669,7 +669,7 @@ describe("FreeText Editor", () => {
             }
           );
 
-          page.evaluate(() => {
+          await page.evaluate(() => {
             window.PDFViewerApplication.eventBus.dispatch(
               "switchannotationeditorparams",
               {
@@ -1290,7 +1290,7 @@ describe("FreeText Editor", () => {
             ".selectedEditor .internal"
           );
 
-          page.evaluate(() => {
+          await page.evaluate(() => {
             window.PDFViewerApplication.eventBus.dispatch(
               "switchannotationeditorparams",
               {

test/integration/highlight_editor_spec.mjs

@@ -626,7 +626,7 @@ describe("Highlight Editor", () => {
           const { width: prevWidth } = await getRect(page, editorSelector);
 
           value = 24;
-          page.evaluate(val => {
+          await page.evaluate(val => {
             window.PDFViewerApplication.eventBus.dispatch(
               "switchannotationeditorparams",
               {
@@ -763,7 +763,7 @@ describe("Highlight Editor", () => {
 
           const { width: prevWidth } = await getRect(page, editorSelector);
 
-          page.evaluate(val => {
+          await page.evaluate(val => {
             window.PDFViewerApplication.eventBus.dispatch(
               "switchannotationeditorparams",
               {

test/integration/ink_editor_spec.mjs

@@ -302,7 +302,7 @@ describe("Ink Editor", () => {
           await page.mouse.up();
           await awaitPromise(clickHandle);
 
-          page.mouse.click(rect.x - 10, rect.y + 10);
+          await page.mouse.click(rect.x - 10, rect.y + 10);
           await page.waitForSelector(`${getEditorSelector(0)}.disabled`);
         })
       );
@@ -583,7 +583,7 @@ describe("Ink Editor", () => {
           }
 
           const red = "#ff0000";
-          page.evaluate(value => {
+          await page.evaluate(value => {
             window.PDFViewerApplication.eventBus.dispatch(
               "switchannotationeditorparams",
               {
@@ -763,7 +763,7 @@ describe("Ink Editor", () => {
           await selectEditor(page, pdfjsA);
 
           const red = "#ff0000";
-          page.evaluate(value => {
+          await page.evaluate(value => {
             window.PDFViewerApplication.eventBus.dispatch(
               "switchannotationeditorparams",
               {