refactor: consistent with_html across platforms

[amrbashir]

What kind of change does this PR introduce?

• Bugfix
• Feature
• Docs
• Code style update
• Refactor
• Build-related changes
• Other, please describe:

Does this PR introduce a breaking change?

• Yes
• No

Checklist

• This PR will resolve #___
• A change file is added if any packages will require a version bump due to this PR per the instructions in the readme.
• I have added a convincing reason for adding this feature, if necessary
• It can be built on all targets and pass CI/CD.

Other information

[wusyong]

Why do we choose null instead of http://localhost? I feel like null origin is more restricted.

[amrbashir]

1. consistency across platforms, Windows already behaves this way.
2. because it doesn't make sense to have an origin when serving a simple HTML string like using data:text/html,, instead, they should be using a custom protocol or a web server