refactor datetime handling & format based on lang

Date format should now be rendered according to the language. Removed 'moment' dependency as we can use built in js to handle timezones as well as formatting. This is one of the tasks in issue #45

package.json

@@ -19,7 +19,6 @@
     "i18next": "^23.10.1",
     "i18next-browser-languagedetector": "^7.2.0",
     "i18next-http-backend": "^2.5.0",
-    "moment-timezone": "^0.5.33",
     "path": "^0.12.7",
     "path-browserify": "^1.0.1",
     "prop-types": "^15.7.2",