Create snes_asm namespace for MosaicEditor code

src/app/asm/script.cc

@@ -0,0 +1,36 @@
+#include "script.h"
+
+#include <asar.h>
+
+#include <array>
+#include <fstream>
+#include <sstream>
+
+#include "absl/status/statusor.h"
+#include "absl/strings/string_view.h"
+#include "app/core/constants.h"
+
+namespace yaze {
+namespace app {
+namespace snes_asm {
+
+absl::StatusOr<absl::string_view> GenerateMosaicChangeAssembly(
+    MosaicArray mosaic_tiles) {
+  std::fstream file("assets/asm/mosaic_change.asm",
+                    std::ios::out | std::ios::in);
+  if (!file.is_open()) {
+    return absl::InvalidArgumentError(
+        "Couldn't open mosaic change template file");
+  }
+  std::stringstream assembly;
+
+  assembly << absl::StrCat("org ", kDefaultMosaicHook);
+  assembly << file.rdbuf();
+
+  file.close();
+  return assembly.str();
+}
+
+}  // namespace snes_asm
+}  // namespace app
+}  // namespace yaze