[js] API for CDP command createIsolatedWorld

[TamsilAmani]

Description

Creating a user-facing API for CDP command Page.createIsolatedWorld

Motivation and Context

Types of changes

• [ ] Bug fix (non-breaking change which fixes an issue)
• [ ] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to change)

Checklist

• [ ] I have read the contributing document.
• [ ] My change requires a change to the documentation.
• [ ] I have updated the documentation accordingly.
• [ ] I have added tests to cover my changes.
• [ ] All new and existing tests passed.

[diemol]

Why do we need this?

[TamsilAmani]

Why do we need this?

In a conversation with @AutomatedTester, he suggested creating an "idealised" API for the CDP command (Page.createIsolatedWorld) as we have for others, for example, pinScript and unpinScript. And in future when we implement BiDi, CDP can be easily replaced by the BiDi code without changing the API signature. @diemol