[Deploy preview] Try fetching every js source during the profile load and have a sanitization option

[canova]

This is only a deploy preview, and not a PR that I intend to land.

I only wanted to get a sense of profile size bloat if I were to fetch all the JS sources in the load time and include them to the profile JSON. This will let us understand how much of a difference it makes, so we can make a more informed decision. The code is written only for testing purposes, it's not really in a good shape.