✨ Add Formstack Trigger (#2066)

* add initial formstack integration configuration

* implement getForms for formstack integration

* implement oauth2 authentication for formstack

* fix formstack color

* enable formstack webhook registration

* remove typeform types

* implement formstack fetch

* ⚡ Improvements to #1673

* ⚡ Improvements

* ⚡ Make work with new async credentials

* ⚡ Improvements

Co-authored-by: Aniruddha Adhikary <aniruddha@adhikary.net>
Co-authored-by: Jan Oberhauser <jan.oberhauser@gmail.com>

packages/nodes-base/credentials/FormstackOAuth2Api.credentials.ts

@@ -0,0 +1,49 @@
+import {
+	ICredentialType,
+	NodePropertyTypes,
+} from 'n8n-workflow';
+
+const scopes: string[] = [];
+
+export class FormstackOAuth2Api implements ICredentialType {
+	name = 'formstackOAuth2Api';
+	extends = [
+		'oAuth2Api',
+	];
+	displayName = 'Formstack OAuth2 API';
+	documentationUrl = 'formstack';
+	properties = [
+		{
+			displayName: 'Authorization URL',
+			name: 'authUrl',
+			type: 'hidden' as NodePropertyTypes,
+			default: 'https://www.formstack.com/api/v2/oauth2/authorize',
+			required: true,
+		},
+		{
+			displayName: 'Access Token URL',
+			name: 'accessTokenUrl',
+			type: 'hidden' as NodePropertyTypes,
+			default: 'https://www.formstack.com/api/v2/oauth2/token',
+			required: true,
+		},
+		{
+			displayName: 'Scope',
+			name: 'scope',
+			type: 'hidden' as NodePropertyTypes,
+			default: scopes.join(' '),
+		},
+		{
+			displayName: 'Auth URI Query Parameters',
+			name: 'authQueryParameters',
+			type: 'hidden' as NodePropertyTypes,
+			default: '',
+		},
+		{
+			displayName: 'Authentication',
+			name: 'authentication',
+			type: 'hidden' as NodePropertyTypes,
+			default: 'header',
+		},
+	];
+}