Add ability to be notified on all text messages, but *not* state events

[dkasak]

Is your feature request related to a problem? Please describe.
Choosing to be notified on "All messages" for a room currently notifies on both text messages and other events such as joins, increasing the badge count for the room (this is describing the behaviour in Element Web/Desktop).

This is a bit awkward from a first-time user experience (FTUE) perspective and is probably not what a typical user would want. This is especially obvious in e.g. company-wide announcement rooms, where you're really only interested in the messages and you want to be notified of messages loudly.

Describe the solution you'd like
Since notifying only on messages is achievable with today's push rules, I propose to

1. Rename the current option to something like All events (messages and state events), and
2. Add a new All messages option which will only notify on actual messages.

Describe alternatives you've considered
Waiting for the new restructured push rules system. That may or may not come, but it's looking like it will not come soon. This proposal is an easy win for usability in the meantime.

[MadLittleMods]

Related issues:

• Add option to only consider message events for marking unread #1088
• Need the ability to prevent people being notified by my name/avatar changes element-web#1544
• Add option to show avatar/displayName changes only for direct chats #337
• Only show joins, etc. for users that have been recently active #1633
• Hide messages displaying changes to room avatar/name/topic and other loud messages … #1089
• Inactive rooms become logs for changes to member avatars/display names element-web#5479
• Rooms incorrectly marked as unread element-web#10954
• Room appears unread when receiving hidden events - RR not sent element-web#4947
• 'All Messages (loud)' setting considers room avatar change and leaves stuck notification element-web#3561

(from #1088)

[ShadowJonathan]

Related: How well does Element currently educate the user what an "event" is? (As opposed to a message)