[Favicons] Speed up favicons

[Spomky]

Version(s) affected

1.2.x

Description

On non-production envs, the Data object is created with the final data in it. It should contain a callback and so that the data is processed only if needed. The SW and Manifest will take advantage on it.

How to reproduce

Enable the favicon feautre with all favicons

Possible Solution

Allow Data to support callbacks

Additional Context

No response