(core) start migrating old tests to work with newer selenium

Summary:
We have an important batch of old browser tests that depend on a pseudo-promise manager selenium's node client used to have. That manager was dropped in v4 (see changelog https://github.com/SeleniumHQ/selenium/blob/trunk/javascript/node/selenium-webdriver/CHANGES.md).

I tried porting some wholesale to our newer style of writing tests, and it is a bit of a bear (and would also be hard work to review). So instead I tried something else: remapping the `webdriverjq` implementation to work with mocha-webdriver. This works pretty well. Some API differences are hard to reconcile, but so far most test code just needs async/await changes to port, meaning a lot less thinking, and probably easier to review overall.

The important property of the ports tests is that they no longer import or require `selenium-webdriver`. mocha-webdriver depends on selenium-webdriver, but a newer version.

I haven't tried dealing with types, since that doesn't matter much - these tests aren't under active development, they are just important for preventing regressions.

Follow up work would be porting the remainder of the tests which, while a slog, I'm hoping is no longer a quagmire. Once the tests are ported, I'd propose moving them to `core`.

Test Plan: Test porting

Reviewers: georgegevoian

Reviewed By: georgegevoian

Differential Revision: https://phab.getgrist.com/D3825

test/nbrowser/gristUtils.ts

@@ -358,8 +358,17 @@ export async function getVisibleGridCellsFast(colOrOptions: any, rowNums?: numbe
 export async function getVisibleDetailCells(col: number|string, rows: number[], section?: string): Promise<string[]>;
 export async function getVisibleDetailCells<T = string>(options: IColSelect<T>): Promise<T[]>;
 export async function getVisibleDetailCells<T>(
-  colOrOptions: number|string|IColSelect<T>, _rowNums?: number[], _section?: string
+  colOrOptions: number|string|IColSelect<T>|IColsSelect<T>, _rowNums?: number[], _section?: string
 ): Promise<T[]> {
+
+  if (typeof colOrOptions === 'object' && 'cols' in colOrOptions) {
+    const {rowNums, section, mapper} = colOrOptions;    // tslint:disable-line:no-shadowed-variable
+    const columns = await Promise.all(colOrOptions.cols.map((oneCol) =>
+      getVisibleDetailCells({col: oneCol, rowNums, section, mapper})));
+    // This zips column-wise data into a flat row-wise array of values.
+    return ([] as T[]).concat(...rowNums.map((r, i) => columns.map((c) => c[i])));
+  }
+
   const {col, rowNums, section, mapper = el => el.getText()}: IColSelect<any> = (
     typeof colOrOptions === 'object' ? colOrOptions :
     { col: colOrOptions, rowNums: _rowNums!, section: _section}
@@ -483,12 +492,13 @@ export async function getCardCount(): Promise<number> {
  * Return the .column-name element for the specified column, which may be specified by full name
  * or index, and may include a section (or will use the active section by default).
  */
-export function getColumnHeader(colOptions: IColHeader): WebElementPromise {
+export function getColumnHeader(colOrColOptions: string|IColHeader): WebElementPromise {
+  const colOptions = typeof colOrColOptions === 'string' ? {col: colOrColOptions} : colOrColOptions;
   const {col, section} = colOptions;
   const sectionElem = section ? getSection(section) : driver.findWait('.active_section', 4000);
   return new WebElementPromise(driver, typeof col === 'number' ?
     sectionElem.find(`.column_name:nth-child(${col + 1})`) :
-    sectionElem.findContent('.column_name', exactMatch(col)));
+    sectionElem.findContent('.column_name .kf_elabel_text', exactMatch(col)).findClosest('.column_name'));
 }
 
 export async function getColumnNames() {