feat!: respect `unhandledPromptBehavior` capability

[sadym-chromium]

BREAKING CHANGE: default behavior changed from ignore to dismiss.

Failing WPT tests should be addressed by https://github.com/web-platform-tests/wpt/pull/46895.

• Puppeteer failures are expected, as Puppeteer has to be updated after Mapper release to pass unhandledPromptBehavior: {default: 'ignore'}.
• chromedriver has to pass the capability to Mapper.

[OrKoN]

the commit is not conventional, although I am not sure it should be a breaking change since it is technically a fix

[sadym-chromium]

the commit is not conventional, although I am not sure it should be a breaking change since it is technically a fix

It's breaking in terms of some work would be required on Puppeteer side to keep API consistent, and some work on chromedriver is required as well.