Implement rollup & .d.ts generator

[narcisbugeag]

Description

This PR implements rollup bundling and .d.ts generator using @microsoft/api-extractor.

Related Issue

#1371

Motivation and Context

How Has This Been Tested?

Types of changes

• [ ] Updated docs / Refactor code / Added a tests case (non-breaking change)
• [ ] Bug fix (non-breaking change which fixes an issue)
• [x] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• [x] 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.
• [ ] I have updated the changelog.

[narcisbugeag]

Apparently, it's not as easy as I'd hoped, there's a bit more work to do on the testing side. 😅