[feat] V1- Support Incoming MFE

[FentPams]

Description

Changes made:

1. Add event listener in loadlazy() to communicate with our MFE, and commented out preview code
2. Write project defined Audiences names into window.hlx for MFE to read
3. Improve the split logic for solving potential split number mismatch with variants number
4. (TBD) add event listener for reloading

See wikis to know more about our MFE: https://wiki.corp.adobe.com/display/AEMSites/Contextual+Experimentation+Roadmap

Related Issue

Motivation and Context

How Has This Been Tested?

Screenshots (if appropriate):

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 signed the Adobe Open Source CLA.
• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.