feat: Add implementation for headless scenario

[mateolis03]

What problem is this solving?

These changes add support for headless implementations, it add new optional fields on the schema to avoid the use of the store-front permissions in a mandatory way, those fields mock the ones fetched originally from the store-front permissions, and also new validations are set in to identify when the requests are sent from a native environment or a headless one.

How to test it?

Workspace

Screenshots or example usage:

How does this PR make you feel? 🔗

[vtex-io-ci-cd]

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