Review types of the last message displayed in room lists

[manuroe]

Element Android and Web do not show join events for example.

The web filter is available at https://github.com/matrix-org/matrix-react-sdk/blob/7ab31932ce99302446b24741ac6e4ee88587766f/src/stores/room-list/MessagePreviewStore.ts#L35

iOS displays much more of them but not reactions.
We need to synchronise with the design team to get the right list of types to display.

[ShadowJonathan]

I'd also like to mention that Android doesn't bump the room list on joins, this creates a counterintuitive situation where a room can be 'read' yet still appear "recent", while unread rooms are below it. I think a common usage pattern is to assess the list of recent unread rooms in one go, and stop at the first unread.

[pixlwave]

For clarity web only shows:

Messages - m.room.message
Call Invite - m.call.invite
Call Answer - m.call.answer
Call Hangup - m.call.hangup
Sticker - m.sticker
Reactions (👍) - m.reaction

[niquewoodhouse]

I think for consistency, we should follow web and android. I did want to discuss this with other designers but I realise the scope of this work is papercuts for iOS. If we change it for iOS here, we won't be making the product less papercutty, we'll just be making it more inconsistent, and for an unknown length of time, because it's not clear when web/android would adapt to a new system.

[pixlwave]

Note - Reactions are not actually shown on web due to a setting that defaults to false here:
https://github.com/matrix-org/matrix-react-sdk/blob/bbc8e4da23d1a3313839ca49bcf0549ccd1d9000/src/settings/Settings.tsx#L230

As these aren't currently shown on iOS, I won't introduce them into the mix.

[pixlwave]

One final tweak - without including create room events, a room with no content appears out of order and has blank labels, so I'm going to add that one back in.

Example without it:

After discussion we decided to replace the create room event's string with "You joined" for the time being and will review that decision in #4918.

[pixlwave]

Additionally added back m.room.encrypted to show unable to decrypt errors when keys are missing, otherwise the same situation as above could occur.