Feature request: allow hiding of read toots

[ericlathrop]

There was a feature I like in the late Sync for Reddit app (R.I.P.) where you it would track posts that you scroll past as "read", and there was button to hide all read posts. I'd love to see this feature in Tusky.

How it would work:

1. scroll through a timeline
2. Tusky marks toots that scroll past the top of the screen as "read". It's important that it only does this when the scrolling is done slowly. Sometimes I fumble my phone around and somehow start scrolling a million pixels a second.
3. a "hide all read" button somewhere will hide all toots marked as read. In the timeline, it should show contiguous spans of read toots similar to how filtered toots are currently displayed. Maybe with a message like "99 read toots", and a "show" link that un-hides that particular group.

It wouldn't have to remember read toots for all time, maybe the last 10,000 or so would be fine.

• I searched or browsed the repo’s other issues to ensure this is not a duplicate.