feat(authmethods): add well typed attribute options (#1972)

Add well typed attribute options to the authmethods proto
definitions, while hiding them from being rendered in
the openapiv2 spec.

internal/proto/controller/api/resources/authmethods/v1/auth_method.proto

@@ -7,9 +7,12 @@ option go_package = "github.com/hashicorp/boundary/sdk/pbs/controller/api/resour
 import "google/protobuf/timestamp.proto";
 import "google/protobuf/wrappers.proto";
 import "google/protobuf/struct.proto";
+import "google/api/visibility.proto";
 import "controller/api/resources/scopes/v1/scope.proto";
 import "controller/custom_options/v1/options.proto";
 
+option (custom_options.v1.domain) = "auth";
+
 // AuthMethod contains all fields related to an Auth Method resource
 message AuthMethod {
   // Output only. The ID of the Auth Method.
@@ -41,8 +44,20 @@ message AuthMethod {
   // The Auth Method type.
   string type = 90;  // @gotags: `class:"public"`
 
-  // The attributes that are applicable for the specific Auth Method type.
-  google.protobuf.Struct attributes = 100 [(custom_options.v1.generate_sdk_option) = true];
+  oneof attrs {
+    // The attributes that are applicable for the specific Auth Method type.
+    google.protobuf.Struct attributes = 100 [(custom_options.v1.generate_sdk_option) = true, (custom_options.v1.subtype) = "default"];
+    PasswordAuthMethodAttributes password_auth_method_attributes = 101 [
+      (custom_options.v1.generate_sdk_option) = true,
+      (custom_options.v1.subtype) = "password",
+      (google.api.field_visibility).restriction = "INTERNAL"
+    ];
+    OidcAuthMethodAttributes oidc_auth_methods_attributes = 102 [
+      (custom_options.v1.generate_sdk_option) = true,
+      (custom_options.v1.subtype) = "oidc",
+      (google.api.field_visibility).restriction = "INTERNAL"
+    ];
+  }
 
   // Output only. Whether this auth method is the primary auth method for it's scope.
   // To change this value update the primary_auth_method_id field on the scope.
@@ -52,7 +67,7 @@ message AuthMethod {
   repeated string authorized_actions = 300 [json_name = "authorized_actions"];  // @gotags: `class:"public"`
 
   // Output only. The authorized actions for the scope's collections.
-  map<string, google.protobuf.ListValue> authorized_collection_actions = 310 [json_name = "authorized_collection_actions"];
+  map<string, google.protobuf.ListValue> authorized_collection_actions = 310 [json_name = "authorized_collection_actions"]; // classified as public via taggable implementation
 }
 
 // The attributes of a password typed auth method.
@@ -191,4 +206,4 @@ message OidcAuthMethodAuthenticateTokenResponse {
   // The status. This will always be "unknown". It will never be forwarded to
   // the consumer.
   string status = 10;  // @gotags: `class:"public"`
-}
+}