App polish part 2 (#1118)

- Fix sheet backgrounds in dark mode.
- Fix background colours for reaction buttons.
- Reply view layout.
- Update separator colours.
- Don't show sender name/avatar in DMs.
- Fix inconsistent line heights with formatted body text.
- Use plain text for reply
- Increase tappable size of collapsed state changes button.
- Blockquote layout and text colour.
- Tap to expand the topic in room details.
- Change the topic and security font size in room details.
- Add cancel button when inviting someone to an existing room.
- Reword Add Friends to Add People in start chat screen.
- Update compound.

ElementX/Sources/Screens/AnalyticsPromptScreen/View/AnalyticsPromptScreen.swift

@@ -51,7 +51,7 @@ struct AnalyticsPromptScreen: View {
                 .foregroundColor(.compound.textSecondary)
             
             Divider()
-                .overlay { Color.compound._borderRowSeparator }
+                .overlay { Color.compound.borderDisabled }
                 .padding(.vertical, 20)
             
             checkmarkList