Room screen: timeline message bubbles (#91)

* #34 Create `TimelineItemStylerView`

* #34 Add styler view into different type of cells

* #34 Use placeholder avatar image on room list

* #34 Add `isOutgoing` param to event based timeline item

* #34 Compute `isOutgoing` for timeline items

* #34 Update sender info view in timeline

* #34 Update mock timeline items

* #34 Rename `EventBasedTimelineView` to `EventBasedTimelineSenderView`

* #34 Change padding on timeline cells

* #34 Create `TimelineItemStylerView` to move content into a bubble if needed

* #34 Use styler view in all of the timeline item views

* #34 Make timestamp more readable on images

* #34 Little layout tweaks

* #34 Add changelog

* #34 Fix code smells

* #34 Set text colors on timeline items

* #34 Fix background color of the timeline

* #34 Fix PR remarks

* #34 Set background colors explicitly on remaining screens

* #34 Reduce min bubble width and make it a scaled metric

* #34 Refactor `PlaceholderAvatarImage` to accept a text only

* #34 Fix code smell

* #34 Fix further comments

ElementX/Sources/Screens/RoomScreen/View/Timeline/FormattedBodyText.swift

@@ -22,10 +22,12 @@ struct FormattedBodyText: View {
                             .frame(width: 4.0)
                         Text(component.attributedString)
                             .fixedSize(horizontal: false, vertical: true)
+                            .foregroundColor(.element.primaryContent)
                     }
                 } else {
                     Text(component.attributedString)
                         .fixedSize(horizontal: false, vertical: true)
+                        .foregroundColor(.element.primaryContent)
                 }
             }
         }