Update pipeline, node, script versions, and fix build error

[Rick-Kirkham]

Change Description:

A. Updates the pipeline to remove E2E tests for IE and Legacy Edge.
B. Updates the required node and npm version ranges.
C. Updates versions for mocha and some Office scripts.
D. Fixes a build error.

The unit test passes, but the E2E tests fail locally in both the master branch and this branch. (The master branch also has a build error that is fixed in this branch by the change to the file test-taskpane.ts.) The remote tests pass.

The local test failure in both branches is that the custom functions are stuck on #BUSY! instead of returning values.

I created an actual project with Yo Office. Then updated the package.json in the project in the same way as in this PR. Then re-ran npm install for the project. The project works including the custom functions, so it's only in the context of local tests that the custom functions are stuck.

Issue for this: Excel-Custom-Functions Issue 453

1. Do these changes impact any npm scripts commands (in package.json)? (e.g., running 'npm run start')
   If Yes, briefly describe what is impacted.
   NO

2. Do these changes impact VS Code debugging options (launch.json)?
   If Yes, briefly describe what is impacted.
   NO

3. Do these changes impact template output? (e.g., add/remove file, update file location, update file contents)
   If Yes, briefly describe what is impacted.
   Yes. See D above.

4. Do these changes impact documentation? (e.g., a tutorial on https://docs.microsoft.com/en-us/office/dev/add-ins/overview/office-add-ins)
   If Yes, briefly describe what is impacted.
   NO.

If you answered yes to any of these please do the following:
> Include 'Rick-Kirkham' in the review
> Make sure the README file is correct

Validation/testing performed:

Does not pass tests locally, but the master branch fails in the same way.

[millerds]

Custom Functions test code seems to have trouble when there is existing cache content from a normal project test deployment ('npm run start') . . . you have to delete the WEF cache in order to ensure the tests pass locally. In the lab it's a fresh box and so the tests don't run into this problem. I think it's something that needs to be changed in the product to fix (cache updates).