Allow users to specify a URL to their own custom blocklists

[Sergey-Lyapin]

Issue Details

By @jaypatrick

Why can't we specify our own blocklists like we can in the various clients, AdGuard Home, etc? In the apps, we can specify our own custom blocklist. Otherwise, I have to keep up with half a dozen custom rule sets on adguard dns servers to keep them synched up with my custom list in github.

The original issue: AdguardTeam/HostlistsRegistry#539

Proposed solution

Allow users to specify a URL to their own custom blocklists.

Alternative solution

No response