Check and log any javascript errors when running theme report

[jonespm]

When we run through the theme report, it would also be useful to check if there are any javascript errors in the custom subaccounts because of a local theme or from a theme change we make.

I believe this is done using this page.on('pageerror') before the page is navigated to.

https://playwright.dev/docs/api/class-page#page-event-page-error