Consolidating uBO rules in one list and serve it from Mullvad CDN (locally?)

On browser startup, a number of domains are contacted to update the uBO blocking rules.

In order to make sure every Mullvad Browser has consistently the same rules, we can merge those lists and server the single list either:

• distributed from the Mullvad CDN and updated at startup
• packed locally and updated when the browser gets updated

First steps:

• review the curate/review the current lists
• merge them in a single file, upload it to the Mullvad CDN
• disable current uBO lists
• add the custom list from the Mullvad CDN

Then if everything goes well:

• enable in Alpha
• consider bundling it locally

In the long run, we should probably remove all the preconfigured lists in uBO.