feature: resource for firewall rule

[KylePeterDavies]

Is your feature request related to a problem? Please describe.

I would like a separate Terraform Resource for Firewall Rules. Over just a Terraform Resource for Firewall. I have found this useful in AWS. As downstream Infrastructure As Code can just add and remove rules.

Describe the solution you'd like

resource "digitalocean_firewall" "firewall" {
  name = "firewall"
}

resource "digitalocean_firewall_rule" "firewall_rue" {
  firewall  = "firewall"
  type      = "inbound"
  port      = 22
  protocol  = "tcp"
  addresses = ["0.0.0.0/0"]
}

Describe alternatives you've considered

N/A

Additional context

See AWS Security Group and AWS Security Group Rule