Update MegaMenu Application Customizer: Version bump to 1.1.0, localization support added, and unnecessary files removed

- Deleted obsolete localization file for English (en-us).
- Updated version number from 1.0.4 to 1.1.0 in manifests.js and manifests.json.
- Added localization support for German (de-de) in a new localization file.
- Removed unnecessary dependencies from manifests.
- Added .gitignore to exclude build artifacts and temporary files.

.gitignore

@@ -0,0 +1,10 @@
+node_modules/
+.tools/
+lib/
+dist/
+temp/
+release/
+sharepoint/solution/
+*.sppkg
+*.tgz
+npm-debug.log*