Bookings: Add new Core Data entity for bookings

[itsmeichigo]

Closes WOOMOB-1374

Description

This PR adds new Booking entity to Core Data for persisting bookings in the local storage.

Testing steps

The new entity is not used yet so just CI passing is sufficient. You can also try building the app from an existing build from trunk to ensure migration succeeds.

Testing information

Added migration test for Core Data model version 126 to 127.

Screenshots

N/A

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• I have considered if this change warrants user-facing release notes and have added them to RELEASE-NOTES.txt if necessary.

[dangermattic]

	1 Warning
⚠️	This PR is larger than 300 lines of changes. Please consider splitting it into smaller PRs for easier and faster reviews.

Generated by 🚫 Danger

[wpmobilebot]

📲 You can test the changes from this Pull Request in WooCommerce iOS Prototype by scanning the QR code below to install the corresponding build.

	App Name	WooCommerce iOS Prototype
	Build Number	pr16167-8d60c5d
	Version	23.3
	Bundle ID	com.automattic.alpha.woocommerce
	Commit	8d60c5d
	Installation URL	1dpml9eh1njv0

Automatticians: You can use our internal self-serve MC tool to give yourself access to those builds if needed.

[RafaelKayumov]

LGTM