Tests:
- `GetDownloadLinks`
- `IncludeRegex` filter works
- `ExcludeRegex` filter works
- `DownloadMinSize` filter works
- only `IncludeRegex` is used when both `IncludeRegex` and `ExcludeRegex` are set
- gets links for all files if none of the above filters are set
- returns null if `torrent.RdId` is null
- `GetTorrents`
- [Both full/partial sync] returns empty list when no torrents present in api response
- [full sync] overrides any previous torrents in cache, deleting those not present in the api response
- [partial sync] updates torrents in cache according to the api response
- [partial sync] adds torrents to cache according to the api response
- `Map` (private so tested via `GetTorrents`)
- Computes progress correctly from `Downloaded / Size`
- `UpdateData`
- [`torrentClientTorrent != null`] does not get from api, updates the `torrent` accordingly
- [`torrentClientTorrent == null`] gets from api, updates the `torrent` accordingly
- [`torrentClientTorrent == null`] when torrent deleted from rd, updates `RdStatusRaw = "deleted""`
- when `torrent.RdId == null`, returns the `torrent` unmodified
