Improvements to state items (#478)

- Remove context menu (and fix long press when there are no items).
- Add membership change tests.
- Fix new/old name incorrect ordering.
- Fix message grouping when it comes before/after a state item from the same user.
- Only show reactions picker for items that can be reacted to.

ElementX/Sources/Services/Timeline/TimelineItemProxy.swift

@@ -37,6 +37,12 @@ enum TimelineItemProxy {
         guard case let .event(selfEventItemProxy) = self, case let .event(previousEventItemProxy) = previousItemProxy else {
             return false
         }
+        
+        // State events aren't rendered as messages so shouldn't be grouped.
+        if selfEventItemProxy.isRoomState || previousEventItemProxy.isRoomState {
+            return false
+        }
+        
         //  can be improved by adding a date threshold
         return previousEventItemProxy.reactions.isEmpty && selfEventItemProxy.sender == previousEventItemProxy.sender
     }
@@ -83,6 +89,10 @@ struct EventTimelineItemProxy: CustomDebugStringConvertible {
         content.asMessage() != nil
     }
     
+    var isRoomState: Bool {
+        content.kind().isRoomState
+    }
+    
     var content: TimelineItemContent {
         item.content()
     }
@@ -116,3 +126,14 @@ struct EventTimelineItemProxy: CustomDebugStringConvertible {
         item.fmtDebug()
     }
 }
+
+extension TimelineItemContentKind {
+    var isRoomState: Bool {
+        switch self {
+        case .state, .roomMembership:
+            return true
+        default:
+            return false
+        }
+    }
+}