[Feature Request] Searchable site list

### Prerequisites

- [X] I [searched for any existing report](https://github.com/darkreader/darkreader/issues?q=is%3Aissue) about this feature request to avoid opening a duplicate.

### Is this feature request related to a problem?

Yes

### Feature Request Description

I would like to be able to search the site list. I have hundereds of entries in it, which are not ordered.

Removing anything from it is not possible in any sane way.

### Screenshots

_No response_

### Additional Context

_No response_