Allow to filter feeds

[pasnox]

Checklist

• I have used the search function for OPEN issues to see if someone else has already submitted the same feature request.
• I have also used the search function for CLOSED issues to see if the feature was already implemented and is just waiting to be released, or if the feature was rejected.
• I will describe the problem with as much detail as possible.
• This request contains only one single feature, not a list of multiple (related) features.

App version

2.9.1

Where did you get the app from

F-Droid

Feature or improvement you want

Allow to filter results.

Why should this be added?

Sometimes I want to come back to an old feed but I can't find it again because it's not possible to filter the list.

Screenshots / Drawings / Technical details

Search in title and content

[spacecowboy]

what do you mean by "filter"?

if you are referring to search then that has already been merged but not released yet

[pasnox]

I mean be able to type a search string and reduce the list of items that match.
Awesome then if it's already merged 😁

[spacecowboy]

Fixed in #647