Replace Pushover with AWS SES (Amazon Simple Email Service)

[rrow010]

This PR adds AWS SES integration as an alternative to Pushover for sending notifications when trial period ends! :-) AWS SES is free: 200 emails per 24-hour period, 1 email per second

Changes include:

• Replace Pushover with AWS SES for email notifications
• Add AWS SSO authentication support
• Update region to ap-southeast-2 (in my case)
• Add comprehensive documentation and setup instructions
• Include requirements file with version constraints
• Add notebook and app files for AWS SES integration

[ed-donner]

Hey @rrow010 this sounds great, but did you push the wrong PR by mistake? Looks like there are 36 files in this, and none of them are in community_contributions as far as I can see... let me know! Thanks Ed