Removal of all references to Singapore entities and proprietary services

[harishpillay]

NOTABUG
I think for this repo to be used without further work, please separate out all references to Singapore and proprietary services.

Now that FormSG is a DPG (https://app.digitalpublicgoods.net/a/10623), the usage by others could be helped with a version that uses non proprietary and fully open source code as noted here https://app.digitalpublicgoods.net/a/10623

How can these closed component(s) be replaced with open alternative(s)?
There are multiple proprietary elements to note: - integrations with proprietary services, like the Singapore National Identity system Singpass. This cannot be replaced, but adopters may replace authentication systems with whatever identity platform of their country, or disable the identity system altogether - AWS SQS: formSG operates on AWS and uses some AWS-specific tools, like SQS for webhook retries. That could be replaced quite easily with open source solutions like RabbitMQ. - FormSG uses AWS SES to send emails. Any other SMTP mailing solution could work. - FormSG uses AWS S3 for its object store. A custom system for storage (even local with a local NAS) - For Monitoring and Observability, FormSG integrates to DataDog. This is mostly non-intrusive in code, and could be replaced with other providers. DataDog is a multi-tool system with tracing, metrics, RUM, etc., each of those could be replaced by something else (open tracing solutions https://opentracing.io/, statsd server https://github.com/statsd/statsd, sentry https://github.com/getsentry/sentry, etc.) - FormSG uses MongoDB (a document database), with the mongoose driver https://www.npmjs.com/package/mongoose. With substantial effort, the database could be replaced with another document database like CouchDB. We have also documented the steps to migrate to FerretDB (an open source MongoDB alternative) here: https://github.com/opengovsg/FormSG/tree/develop?tab=readme-ov-file#migrating-from-mongodb-to-ferretdb

[harishpillay]

Thanks for moving this.