Add eslint n/no-restricted-import, n/no-restricted-require

Disallows Node-style imports like 'console', and paths missing the .js extension. Fixed resulting warnings.

This plugin has some rules which are sort of redundant with built-in ones, but these work much better.

Issue: #3702

Requirements for PR author:

[n/a] All missing test coverage is tracked with "TODO" or .unimplemented().
[n/a] New helpers are /** documented */ and new helper files are found in helper_index.txt.
[n/a] Test behaves as expected in a WebGPU implementation. (If not passing, explain above.)
[n/a] Test have be tested with compatibility mode validation enabled and behave as expected. (If not passing, explain above.)

Requirements for reviewer sign-off:

[n/a] Tests are properly located in the test tree.
[n/a] Test descriptions allow a reader to "read only the test plans and evaluate coverage completeness", and accurately reflect the test code.
[n/a] Tests provide complete coverage (including validation control cases). Missing coverage MUST be covered by TODOs.
[ ] Helpers and types promote readability and maintainability.

When landing this PR, be sure to make any necessary issue status updates.

gpuweb / cts