fix(dialog): remove focus trap focus listeners onRemove

[Splaktar]

PR Checklist

Please check that your PR fulfills the following requirements:

• The commit message follows our guidelines
• Tests for the changes have been added or this is not a bug fix / enhancement
• Docs have been added, updated, or were not required

PR Type

What kind of change does this PR introduce?

[x] Bugfix
[ ] Enhancement
[ ] Documentation content changes
[ ] Code style update (formatting, local variables)
[ ] Refactoring (no functional changes, no api changes)
[ ] Build related changes
[ ] CI related changes
[ ] Infrastructure changes
[ ] Other... Please describe:

What is the current behavior?

In MdDialogProvider.onRemove(), we currently call removeChild() on the topFocusTrap and bottomFocusTrap for the dialog and we let the browser handle GC'ing those detached Nodes. But we don't remove the 'focus' event listeners for each of these Nodes.

Issue Number:
Relates to #11207. Closes #12010.

What is the new behavior?

• remove focus trap focus event listeners in MdDialogProvider.onRemove()
• improve JSDoc and Closure types
• fix typos
• simplify isNodeOneOf() and ensure it returns a boolean
• fix location of comments in dialog demo
• apply some npm audit fixes to package-lock.json

Does this PR introduce a breaking change?

[ ] Yes
[x] No

Other information

This doesn't seem to have a noticeable impact on the overall number of listeners when profiling.

Before

After

[andrewseguin]

LGTM - in the future, it would be easier to review these if you can separate out the formatting changes in a separate commit. I assume this is an auto-format done based on changed files, so perhaps you can touch each file to format them, then commit, then make your change.