Refactor migration libraries API

[VellummyilumVinoth]

Description

This PR resolves comments for the PR: #636 (comment)

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[xlight05]

Is this the pattern we use in this codebase?

Not a big fan of this since it only has a normal class with static process function?

[xlight05]

Seems like other usages don't use visitors either. If the handlers are short, we can revert back to handling it here itself.

[xlight05]

Check if theres a kind or type which we can do instanceof. There is, we should follow that approach

[xlight05]

Lets address these too before merging this to main

[xlight05]

Seems like other usages don't use visitors either. If the handlers are short, we can revert back to handling it here itself.

[xlight05]

We should move Copilot sepcific stuff to a package inside core