Allow filtering /api/entries by http_status

[voltagex]

Is your feature request related to a problem? Please describe.
It'd be nice to be able to filter by http_status so I could easily see all the pages that might appear to have been archived correctly but got redirected or were 404

Sidenote: there's a UI issue here where entries that were 404 when archived are not shown any differently

Describe the solution you'd like
Add http_status (and possibly other headers) as filter options in the API

Describe alternatives you've considered
I am currently writing code against the API to do a semi-automated check, which is how I ran into this

[HolgerAusB]

I agree, that would be nice. Specially when (massively) using third party link-sharing, to push an URL to wallabag without getting an immediate response of failure, e.g. when using a smartphone. But please consider to have this on the UI too.

[j0k3r]

I agree too and that should be a hard PR to make.