feat: export backdrop component [LW-10640]

Author: DominikGuzei

.gitignore

@@ -14,3 +14,6 @@
 dist
 node_modules
 storybook-static
+
+# Intellij IDEs
+.idea

src/design-system/index.ts

@@ -64,3 +64,4 @@ export * from './auto-suggest-box';
 export * from './table';
 export { InfoBar } from './info-bar';
 export * from './address-tags';
+export * from './backdrop';