Updated NPM packages

[ArturAmpilogov]

• Removed @google-cloud/firestore dependency. Starting from firebase-admin v10 it is possible to import FieldValue, FieldPath directly from the package.
• Rewrote firebase-admin import to modular style (const { initializeApp } = require('firebase-admin/app')).
• Moved firebase-admin to peerDependencies.
• For local usage upgraded firebase-admin to v11.
• Upgraded @firebase/rules-unit-testing and the relative code for testing.
• Upgraded firebase-tools dev dependency.

[KoenLippe]

Just today I ran into some problems regarding the mismatch of my functions project which uses firebase-admin and fireway which uses @google-cloud/firestore. This resulted in errors regarding the mismatch of types between the packages.

I figured that if fireway was based on firebase-admin it would solve my problems. Came here to see if someone else already did something like this, thanks!

+1 for this PR

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What is the main difference between these two packages?

[ArturAmpilogov]

It looks that @kevlened is busy and does not have much time to support this awesome project.

So, I've made a lot of changes and improvements and published the new version at @dev-aces/fireway.
It needs some updates, like moving tests to jest, providing -add option to add a migration file, set up Github workflow. But those are less critical.