Add expand/collapse UI for reactions (#1249)

* Add expand/collapse UI for reactions

- Adds a CollapsibleFlowLayout for controlling the layout
- Adds tests for  this layout and some mocks for testing layouts generally
- Improves the rendering of the reaction buttons which were not pixel perfect
- Adds the UI for the expand collapse buttons including the count of hidden items in the collapsed state.

* Add comment for reactionsCollapsed binding.

* Remove Flow and simplify implementation

- Remove SwiftUI-Flow
- Add strings by importing from Localyse
- Remove count on expand button as requires GeometryReader and can cause loops
- Don't use GeometryReader for hiding reactions with opacity(just put them way off screen for now)
- Fix unit and UI tests

* Address PR comments

- use synthesized inits
- use rows rather than lines for naming flow layout
- other naming improvements
- reactions were already rendered in another ui test, removing my test on favour of those and updating the screenshots for those.

ElementX/Sources/Other/SwiftUI/Layout/ViewFrameReader.swift

@@ -28,12 +28,13 @@ import SwiftUI
 /// ```
 struct ViewFrameReader: View {
     @Binding var frame: CGRect
+    let coordinateSpace: CoordinateSpace = .local
     
     var body: some View {
         GeometryReader { geometry in
             Color.clear
                 .preference(key: FramePreferenceKey.self,
-                            value: geometry.frame(in: .local))
+                            value: geometry.frame(in: coordinateSpace))
         }
         .onPreferenceChange(FramePreferenceKey.self) { newValue in
             guard frame != newValue else { return }