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/source/download.cpp

@@ -38,7 +38,7 @@ Mutex g_mutex_share[CURL_LOCK_DATA_LAST]{};
 
 struct DataStruct {
     std::vector<u8> data;
-    u64 offset{};
+    s64 offset{};
     FsFile f{};
     s64 file_offset{};
 };