vultr_ssh_keys - no way to get all keys and general usability

[baznikin]

Describe the bug
With vultr_ssh_keys no way to specify no filter {} or specify "empty" filter or specify "catch-all" filter, or poorly documented.

To Reproduce

I tried following variants:

# produce error "no results were found"
data "vultr_ssh_key" "vultr_ssh_keys" {
  filter {
    name = "empty"
    values = []
  }
}

data "vultr_ssh_key" "vultr_ssh_keys" {
  filter {
    name = "name"
    values = []
  }
}

data "vultr_ssh_key" "vultr_ssh_keys" {
  filter {
    name = "name"
    values = ["*"]
  }
}

data "vultr_ssh_key" "vultr_ssh_keys" {
  filter {
    name = "name"
    values = ["."]
  }
}

# produce error "name required", "value required"
data "vultr_ssh_key" "vultr_ssh_keys" {
  filter {  }
}

Additional info
Between values returned I see no key ID, so basically this data method is useless for usage with vultr_instance anyway... See digitalocean_ssh_keys as example of good realization.

Expected behavior
List of all existent keys returned. Returned values include key ID.

[optik-aper]

I agree that there should be a way for the filter to return all. I'll look into this.