LZVS-2611: Fix several issues and add SNS enhancement

[michelfasen-nhs]

Description

• Modified modules/aws-backup-source/backup_plan.tf and modules/aws-backup-source/backup_restore_testing.tf
  • Add environment_name tag to all Backup Plans to prevent Backup Framework reporting account as not compliant
  • Fix Aurora selection plan which was ignoring non-default value tag
• Modified modules/aws-backup-destination/parameter_store_kms.tf
  • Use "var.name_prefix" for KMS Alias to allow multiple source accounts to backup to one destination account
• Modified modules/aws-backup-source/backup_notification.tf and modules/aws-backup-source/sns.tf
  • Add support for additional SNS subscribers to support Lambda, SQS, HTTP etc.

Non-breaking changes unless you directly point to the Parameter Store KMS Alias outside this Backup Template.

[TurboNHS]

@michelfasen-nhs It would be nice if you could separate these two into two separate PRs.

I'm somewhat interested in your SNS stuff, but I'm also already doing some of what you're doing (especially modules/aws-backup-source/backup_restore_testing.tf).

Not saying mine's better than yours, and I'm perfectly fine on rebasing mine if yours get merged first, but it might be .. "quicker" (!?) to have it/"them" approved and merged if there's two separate .. "things" being worked on.. ?