Graph improvement and extra statistic

### Prerequisites

- [X] I have checked the [Wiki](https://github.com/AdguardTeam/AdGuardHome/wiki) and [Discussions](https://github.com/AdguardTeam/AdGuardHome/discussions) and found no answer

- [X] I have searched other issues and found no duplicates

- [X] I want to request a feature or enhancement and not ask a question

### The problem

I miss a way to change the graph time span.
I want to keep the 90 days of statistics, without it changing the graphs at the dashboard to a 90 day line.
It would be amazing if there was a different setting to change how (time-) wide the graph shows.
For example a 90 days to keep statistics
And the dashboard shows the last 24h, or the data since midnight, or since Monday... However we desire.

And the other statistic is simply the number of unique domains that are blacklisted.
I got a 15 ish lists of domains to block
All together a milion entries, but I bet if I was able to see how many unique there are I would only be at a 400K instead. But Idk 😀 I can't find it anywhere.

### Proposed solution

A quick setting at the dashboard or in general settings a section where we can change the graphs/dashboards time span (or however it's called.) where we can chose between 24h, 7 days, 30 days, restart at midnight, restart every Monday, every 1st of the month... Etc.

And a simple counter in the blacklist tab on top, with 'unique entries' or a exporter, that exports all domains of all lists it filters on (with no dubbels ofcourse) to a CSV or text file. So it's one new full list of domains.

### Alternatives considered and additional information

Anything is possible, maybe there are people with even better idea's to get the same result.