Add a "Report room" to the room setting menu

[bmarty]

In the room settings, add a way for the user to report the room

New item "Report room" can be added above Leave room. Clicking on it will open a dialog to eventually provide a reason (or cancel) and submitted the dialog will invoke the report content API with the eventId of the state event m.room.create.

Once reported, a confirmation dialog will be shown, similar to the dialog shown when reporting a specific event.

The "Report room" action will not be displayed for DM, only for rooms.

[BillCarsonFr]

I think we probably want to always add the button to report the room.

There are legitimate cases to report a DM room, as an example you could get invited to start a chat in a room that you will want to report. Some spammer could also trick you to see a room as a DM (is_direct in invite)?

However, if a DM, the action could both report the room and the user who created the room.