Stripe Link File Delivery 1.2.0

Massive performance improvements:

1. Added Memory recommendation, ensuring 1 full vCPU provisioning
2. Removed aws-sdk dependency and replaced it with aws-sdk-js-v3 modules for signinf and s3, idea credit Mykhailo Matviiv. 6MB total package, 1200ms cold, 400ms hot.
3. Changed the email sending method to a non-blocking call since the reply isn't used in any way other then logging, idea credit Mykhailo Matviiv and Lambda non-blocking tips from sensedeep. 6MB total package, 1200ms cold, 400ms hot.
4. Fully removed the import of AWS SDK, added type: module to package.json to rely on AWS Lambda's built-in shipped AWS SDK V3. 2.25MB total package, 1000ms cold, 350ms hot.
5. Added webpack build step to further reduce the package size, tree-shake it and minmize. 78KB total package, 750ms cold, 200ms hot.
6. Replaced Axios with https and url, webpack with esbuild. 32KB total package, 720ms cold, 180ms hot.