Add sourcemap to tobago-bundle.js

Sourcemap is now generated from rollup for better debugging purpose.

issue: TOBAGO-1633: TS refactoring
diff --git a/tobago-theme/tobago-theme-standard/src/main/npm/rollup.config.js b/tobago-theme/tobago-theme-standard/src/main/npm/rollup.config.js
index 13f8a1c..d59e238 100644
--- a/tobago-theme/tobago-theme-standard/src/main/npm/rollup.config.js
+++ b/tobago-theme/tobago-theme-standard/src/main/npm/rollup.config.js
@@ -22,6 +22,7 @@
   output: {
     file: 'js/tobago-bundle.js',
     format: 'iife',
+    sourcemap: true,
     name: 'tobago'
   },
   plugins: [