Add possibility to compress state file when using gcs remote state

[diraol]

Current Terraform Version

v0.11.14 and v0.12.12

Use-cases

Similarly to #20328, it would be awesome to be able to handle terraform state files in a compressed way (while storing or retrieving it from the remote backend). In some cases this can save tons of MBs per execution, increasing speed (by reducing the number of transferred bytes) and reducing costs (bandwidth). Especially in large projects.

Proposal

terraform {
  backend "gcs" {
    bucket  = "my-bucket"
    prefix  = "terraform/state"
    compression = true
  }
}

References

• Add possibility to compress state file when using s3 remote state #20328