Inconsistent notification priorities and missing conversation feature

### Steps to reproduce

Where are you starting? What can you see?

When receiving notifications in different rooms, some are sent in the silent notification channel, others in the noisy channel and only one room so far could send a notification with the conversation feature (https://developer.android.com/develop/ui/views/notifications/conversations ).

### Outcome

#### What did you expect?

To first have clear UI settings to set the notification priority for each room. I figured out, that adding a room to the favorites makes the notification noisy, but that seems not very intuitive.

And secondly to have the conversations feature implemented. This allows setting custom priorities, ringtones etc. from within the android settings itself.
That is stopping me right now from migrating to Element X from Classic.

#### What happened instead?

As described previously it is not intuitive to set the notification priority of a room and the conversations feature is completely missing, although Element Classic had it.

### Your phone model

Using multiple phones, all are effected

### Operating system version

Android 15

### Application version and app store

26.01.2 (F-Droid)

### Homeserver

Synapse

### Will you send logs?

No

### Are you willing to provide a PR?

No