Default URL when using Happy DOM as environment

[capricorn86]

Clear and concise description of the problem

Happy DOM and JSDOM both default the URL to "about:blank". For the JSDOM environment the URL is set to "http://localhost:3000", while when using Happy DOM it has not been set to any default value.

This is causing issues when constructing relative URLs (see capricorn86/happy-dom#868).

Suggested solution

My suggestion is to default the Happy DOM URL to the same URL as JSDOM (which is "http://localhost:3000").

Alternative

No response

Additional context

No response

Validations

• Follow our Code of Conduct
• Read the Contributing Guidelines.
• Read the docs.
• Check that there isn't already an issue that request the same feature to avoid creating a duplicate.

[capricorn86]

Relates to #3903