Add Prefect on AWS EKS recipe

[EmilRex]

Description

Adds a recipe for creating a new EC2 backed EKS cluster on AWS and deploying a Prefect agent using Helm.

Type of change

• [x] New feature (non-breaking change which adds functionality)

New Recipe Checklist

• [x] My PR is in the format of Add <project-name> recipe
• [x] My recipe is reproducible and explains everything needed to run successfully. If my code has external dependencies, I make mention of them.
• [x] My code is easily understandable and/or well-commented.