Add Apache Skywalking Terraform Module

Goal: ○ To add a Terraform module for SkyWalking deployment to facilitate users in conveniently spinning up a cluster for demonstration or testing. ○ To allow users to customize the Terraform provider according to their needs, making it feasible for them to use it in their production environment. ○ To mainly focus on the support for AWS in the Terraform module for SkyWalking deployment. ○ To provide a hassle-free solution to users where they only need to provide their access key/secret key, and the Terraform provider does the rest of the work, which includes creating VMs, creating database/OpenSearch or RDS, downloading SkyWalking tars, configuring the SkyWalking, and starting the SkyWalking components (OAP/UI), creating public IPs/domain name, etc.