Add a helper tool for preparing "registeredScripts"

The script rules can be known to us (i.e. they exist in one of AdGuard filters) or unknown (added by the user, received from a custom filter).

Known script rules are applied via `browser.scripting.executeScript` which is a safer way that allows to avoid issues with websites' CSP.
Therefore, the library users will naturally be interested in composing this "known script rules" list.

We have several options here:
1. Provide a separate helper tool that will re-compile the registered script rules list.
2. Automatically publish an NPM module with the latest "script rules" and advise to use it (this can be done similarly to how `dnr-rulesets` are prepared).
3. Bundle it within `@adguard/safari-extension` and publish automatically.

So far I like the second approach more.