Add support for relative assets handling in built in server

[Inori-dokusha]

Check for existing issues

• Completed

Describe the bug / provide steps to reproduce it

When the html file is liveserver, it will not be connected to the CSS in a different folder but in one folder as its parent.

Environment

• Android 11
• Acode 1.10.5
• Webview 132.0.6834.14

If applicable, add mockups / screenshots regarding your vission

No response

If applicable, attach your Acode.log file to this issue.

Acode.log