remove unused exports to clean up code

[SgtPooki]

Part of #1965

• run npx -y ts-unused-exports tsconfig.json {src,test}/**/*.js and get rid of any exports that are unused.
• run npx -y unused-exports --path ./src --ignore node_modules/ and get rid of any exports that are unused
• run https://github.com/MatthieuLemoine/unused-webpack-plugin and enable failOnUnused
• Remove any dead code

[SgtPooki]

+    new UnusedWebpackPlugin({
+      // Source directories
+      directories: [path.join(__dirname, 'src'), path.join(__dirname, 'test')],
+      // Exclude patterns
+      exclude: ['*.stories.*', '*.test.*', '**/fixtures/**'],
+      // Root directory (optional)
+      root: __dirname,
+      failOnUnused: true