With LL, sometimes the FilePanel filter gets applied to the main timeline

[bwindels]

If you start using the FilePanel view, it seems that the main timeline can now get stuck in FilePanel view too after a refresh or backgrounding/foregrounding; all my rooms are only showing attachments only currently(!). This looks like it was only happening in the clientside filter, as (luckily) refreshing the page fixed it.

[bwindels]

Split of from #7182

[bwindels]

@ara4n wrote:
I just reproduced the FilePanel problem:

• I joined a room. Before(?) the LL members synced up, i clicked on the FilePanel icon. I didn't try scrolling the FilePanel.
• I then started paginating backwards in the main timeline
• The only things which showed up in the scrollback for the main timeline were filtered files; no normal messages.

In other news, we should split this bug up into separate ones... i only dumped it all in one place due to expedience/laziness whilst on hol.