feat(input): add host input remapping

Add compact keyboard and mouse mapping with analog-stick defaults and integrate a global remapping editor into the Qt launcher.

Based on the host input remapping work from PR #109.

Co-authored-by: DistantMyth <thetarun3@gmail.com>

src/common/emulatorConfig.cpp

@@ -101,4 +101,8 @@ bool ReadbackLinearImagesEnabled() {
 	return g_config->readback_linear_images;
 }
 
+const Keymap& GetKeymap() {
+	return g_config->keymap;
+}
+
 } // namespace Config