Request: spacelift_contexts data source label filter

[dylan-turnbull]

The spacelift_contexts could be improved with the option to supply labels that would be used to filter the returned list of contexts.

While the list can be filtered after being returned by the provider, provider side filtering would result in much cleaner Terraform configuration

# An example of what the implementation could look like
data "spacelift_contexts" "contexts" {
  labels = [
    "production",
    "vault"
  ]
}

# An example of similar functionality in the AWS Terraform provider.
data "aws_subnets" "private" {
  tags = {
    Tier = "Private"
  }
}

[marcinwyszynski]

Make sense, I'll take this one.

[marcinwyszynski]

This is released in 0.1.37.