feat(Citrix ADC): add Citrix ADC node (#4274)

* ✨ Citrix ADC node

* 🐛 Fix typo in codex file

* ⚡ Remove trailing slash if there is one

* ⚡ Add certificate resource

* 🐛 Fix merge conflict issue

packages/nodes-base/nodes/Citrix/ADC/GenericFunctions.ts

@@ -0,0 +1,44 @@
+import { OptionsWithUri } from 'request';
+
+import { IExecuteFunctions, ILoadOptionsFunctions } from 'n8n-core';
+
+import {
+	IDataObject,
+	IHookFunctions,
+	IWebhookFunctions,
+	JsonObject,
+	NodeApiError,
+} from 'n8n-workflow';
+
+export async function citrixADCApiRequest(
+	this: IExecuteFunctions | IWebhookFunctions | IHookFunctions | ILoadOptionsFunctions,
+	method: string,
+	resource: string,
+	body: IDataObject = {},
+	qs: IDataObject = {},
+	uri?: string,
+	option: IDataObject = {},
+	// tslint:disable-next-line:no-any
+	): Promise<any> {
+
+	const { url } = (await this.getCredentials('citrixAdcApi')) as { url: string };
+
+	let options: OptionsWithUri = {
+		headers: {
+			'Content-Type': 'application/json',
+		},
+		method,
+		body,
+		qs,
+		uri: uri || `${url.replace(new RegExp('/$'), '')}/nitro/v1${resource}`,
+		json: true,
+	};
+
+	options = Object.assign({}, options, option);
+
+	try {
+		return await this.helpers.requestWithAuthentication.call(this, 'citrixAdcApi', options);
+	} catch (error) {
+		throw new NodeApiError(this.getNode(), error as JsonObject);
+	}
+}