Docs: Add the ability to install the ebs_csi_driver in the eks bootstrap script

What does this MR do?

Adds functions in support of installing the AWS EBS CSI Driver which is required for EKS clusters version 1.23 or greater.

Installing the add-on is minimally a three step process:

1. Creating an IAM OIDC provider: https://docs.aws.amazon.com/eks/latest/userguide/enable-iam-roles-for-service-accounts.html
2. Creating a IAM role for the EBS CSI Driver service account: https://docs.aws.amazon.com/eks/latest/userguide/csi-iam-role.html
3. Installing the add-on: https://docs.aws.amazon.com/eks/latest/userguide/managing-ebs-csi.html

This adds a ./eks_bootstrap_script add_ebs_csi_driver command to run these three steps, as well as show a notice on the up command that the EBS CSI Driver needs to be installed.

Related issues

Closes #4510 (closed)

Testing

Use the eks_bootstrap_script as normal with the up command to create a EKS cluster >= version 1.23

Observe that the up command will display:

2023-04-10 13:58:25 [✔]  EKS cluster "gitlab-cluster-aws" in "us-east-2" region is ready
EKS Clusters >= 1.23 need the AWS EBS CSI Driver installed.
Please see: https://docs.aws.amazon.com/eks/latest/userguide/ebs-csi.html
Use this script with the add_ebs_csi_driver command to install the driver.

Install the driver with ./eks_bootstrap_script add_ebs_csi_driver and observe that things are created correctly and that the ebs-csi-controller is created successfully.

Subsequent installs should recognize that the add-on is already installed and display:

./eks_bootstrap_script add_ebs_csi_driver
EBS CSI Driver is already installed. Version: v1.17.0-eksbuild.1

Checklist

See Definition of done.

For anything in this list which will not be completed, please provide a reason in the MR discussion.

Required

• Merge Request Title and Description are up to date, accurate, and descriptive
• MR targeting the appropriate branch
• [ ] MR has a green pipeline on GitLab.com
• When ready for review, MR is labeled "~workflow::ready for review" per the Distribution MR workflow

Expected (please provide an explanation if not completing)

• Test plan indicating conditions for success has been posted and passes
• Documentation created/updated
• [ ] Tests added
• Integration tests added to GitLab QA
• Equivalent MR/issue for omnibus-gitlab opened
• Validate potential values for new configuration settings. Formats such as integer 10, duration 10s, URI scheme://user:passwd@host:port may require quotation or other special handling when rendered in a template and written to a configuration file.