feat(Slack Node): Update wait for approval to use markdown (#11754)

packages/nodes-base/nodes/Slack/V2/MessageInterface.ts

@@ -3,3 +3,36 @@ export interface IAttachment {
 		item?: object[];
 	};
 }
+
+// Used for SendAndWaitMessage
+export interface TextBlock {
+	type: string;
+	text: string;
+	emoji?: boolean;
+}
+
+export interface SectionBlock {
+	type: 'section';
+	text: TextBlock;
+}
+
+export interface DividerBlock {
+	type: 'divider';
+}
+
+export interface ButtonElement {
+	type: 'button';
+	style?: 'primary';
+	text: TextBlock;
+	url: string;
+}
+
+export interface ActionsBlock {
+	type: 'actions';
+	elements: ButtonElement[];
+}
+
+export interface SendAndWaitMessageBody {
+	channel: string;
+	blocks: Array<DividerBlock | SectionBlock | ActionsBlock>;
+}