add touch support (#77)

* initial work on touch support

* add touch support to all objects

* add touch scrolling, fix scrollbar, fix appstore search

- when fireing an action, the action array may change. so the loop should break early as soon as an action is handled.
  this fixes the appstore search when pressing B.
- scrollbar no longer goes oob. fixes #76

currently, scrolling has no acceleration.

sphaira/include/ui/progress_box.hpp

@@ -22,7 +22,7 @@ struct ProgressBox final : Widget {
     auto Draw(NVGcontext* vg, Theme* theme) -> void override;
 
     auto NewTransfer(const std::string& transfer) -> ProgressBox&;
-    auto UpdateTransfer(u64 offset, u64 size) -> ProgressBox&;
+    auto UpdateTransfer(s64 offset, s64 size) -> ProgressBox&;
     void RequestExit();
     auto ShouldExit() -> bool;
 
@@ -55,8 +55,8 @@ private:
     ProgressBoxDoneCallback m_done{};
     std::string m_title{};
     std::string m_transfer{};
-    u64 m_size{};
-    u64 m_offset{};
+    s64 m_size{};
+    s64 m_offset{};
     bool m_exit_requested{};
 };