update: Install EKS addons manually where appropriate

### What would you like to be added?

Where there are modules that focus on capabilities of a specific addon this addon should be manually installed instead of being done through the Terraform.

There is two main pieces of work to be done.

First is to create a reusable script to delete an EKS addon if its installed, similar to the delete-nodegroup script https://github.com/aws-samples/eks-workshop-v2/blob/main/lab/bin/delete-nodegroup This must check the addon is present before deleting.

Second is to implement this in each lab that should use this model:

- [x] Fundamentals - Storage - EBS
- [x] Fundamentals - Storage - EFS
- [ ] Observability - EKS open source observability
- [ ] Observability - Container Insights on EKS

Addons should be created with resolve conflicts set to `OVERWRITE` and deleted with the preserve flag disabled.

### Why is this needed?

The current model obscures how these addons are installed and configured, and we should illustrate this instead.