Amendment list: Navigation between filtered items doesn't work correctly

[MSoeb]

Describe the bug
The amendment list has a navigation bug if a filter is active. The navigation between amendments is always accross ALL amendments not only between the filtered ones.

How to Reproduce
Steps to reproduce the behavior:

1. open a meeting
2. open motions and create a few motions with amendments in different states
3. open the amendment list and filter by a state. Open the last amendment and try too navigate. You can navigate now between all amendments, not the filtered items.

Expected behavior
If a filter is active in the amendment list, the navigation between the amendments should only be possible in the filtered amendments.

Additional context

[MSoeb]

We have to discuss how we want to handle the navigation between motions in general.