LPAL-556 remove non regional key

[williamfalconeruk]

Purpose

to schedule key deletion of the non regional key, and to add new eu-west-2 aws creds (London) in preparation for trying out DR practice.

Fixes LPAL-556

Approach

revert previous terraform for CMK
Add region credentials for London.

Learning

2 items not in AWS provider as yet means we have to do these outside of the Terraform:

• Cross Region RDS Snapshot replication:(vote for this please!) - Request to implement the API call StartDBInstanceAutomatedBackupsReplication hashicorp/terraform-provider-aws#20606
• Cross region CMKs - on the roadmap for release by Oct 2021: Support for KMS Multi-Region Keys hashicorp/terraform-provider-aws#19896

Nonetheless we'll continue to experiment with creating a stood up version in London using the CLI / Console as an approach.

Checklist

• I have performed a self-review of my own code
• I have updated documentation (Confluence/GitHub wiki/tech debt doc) where relevant
• I have added tests to prove my work
• I have added mandatory tags to terraformed resources, where possible
• If I added a package.json or composer.json, I also made sure this is included in the script in .github/workflows/dependabot-update.yml
• The product team have tested these changes