Create EKS cluster Vue app skeleton

What does this MR do?

This MR creates the initial skeleton for Create AWS EKS Cluster Vue application following the frontend development guidelines. The create EKS cluster feature is documented on https://gitlab.com/gitlab-org/gitlab-ce/issues/46686. This application only encompasses the form to enter the service credentials to access the AWS SDK API and the form to configure the EKS cluster.

Architecture Overview

Dependencies introduced

This MR introduces a new dependency to the front-end stack: The AWS SDK for JavaScript. I decided to include it as a node package because it allows us to import the subset of the SDK that we need. See the Node.JS section of this document: https://docs.aws.amazon.com/AWSJavaScriptSDK/latest/.