v0.3.x is breaking the usage of KMS key

[mmiranda]

It seems the new version 0.3.x broke the usage of KMS keys instead of public/private key.

As I can see, according to the comment https://github.com/syndbg/terraform-provider-vaulted-null/blob/main/internal/provider/provider.go#L191-L193

// NOTE: AWS KMS Asymmetric encryption is assumed.
// Public key here would be one retrieved from AWS KMS.
publicKey, err := readPublicKey(d, osExecutor, rsaSvc)

the method readPublicKey always expects the param public_key_content and completely ignores the kms usage.

func readPublicKey(
   d *schema.ResourceData,
   osExecutor os.OsExecutor,
   rsaSvc *rsa.Service,
) (*stdRsa.PublicKey, error) {
   var publicKey *stdRsa.PublicKey

   publicKeyContentTypeless := d.Get("public_key_content")

[maxforasteiro]

this is a solution attempt: #11

Since there are no tests, I'm not sure if I'm breaking any other expected behavior