✨ Add Paddle Integration (#726)

* 🚧 Resource descriptions

* 🚧 Node logic / Genericfunctions setup

* 🚧 Tests / changes

* 🚧 Changes

- Added loadOptions to Payments / Coupon properties for easier item selection
- Added exemptions for how data is returned due to inconsistent data return object from API
- Other small fixes in main node

* 🚧 Simplified HTTPS error response

* 🚧 Added RAW Data options

* 🔥 Removed order resource

- Cannot fetch order without a checkout ID, which can only be obtained via a custom implementation which involves a callback function when a user goes through their checkout process.

* ⚡ Improvement to Paddle-Node

* ⚡ Improvements

* ⚡ Added all currencies, discount grouped properties to coupon update

Co-authored-by: ricardo <ricardoespinoza105@gmail.com>

packages/nodes-base/nodes/Paddle/GenericFunctions.ts

@@ -0,0 +1,76 @@
+import {
+	OptionsWithUri,
+} from 'request';
+
+import {
+	IExecuteFunctions,
+	IHookFunctions,
+	ILoadOptionsFunctions,
+	IExecuteSingleFunctions,
+	IWebhookFunctions,
+} from 'n8n-core';
+
+import {
+	IDataObject,
+} from 'n8n-workflow';
+
+export async function paddleApiRequest(this: IHookFunctions | IExecuteFunctions | IExecuteSingleFunctions | ILoadOptionsFunctions | IWebhookFunctions, endpoint: string, method: string, body: any = {}, query?: IDataObject, uri?: string): Promise<any> { // tslint:disable-line:no-any
+	const credentials = this.getCredentials('paddleApi');
+
+	if (credentials === undefined) {
+		throw new Error('Could not retrieve credentials!');
+	}
+
+	const options : OptionsWithUri = {
+		method,
+		headers: {
+			'content-type': 'application/json'
+		},
+		uri: `https://vendors.paddle.com/api${endpoint}` ,
+		body,
+		json: true
+	};
+
+	body['vendor_id'] = credentials.vendorId;
+	body['vendor_auth_code'] = credentials.vendorAuthCode;
+	try {
+		const response = await this.helpers.request!(options);
+
+		if (!response.success) {
+			throw new Error(`Code: ${response.error.code}. Message: ${response.error.message}`);
+		}
+
+		return response;
+	} catch (error) {
+		throw new Error(`ERROR: Code: ${error.code}. Message: ${error.message}`);
+	}
+}
+
+export async function paddleApiRequestAllItems(this: IHookFunctions | IExecuteFunctions, propertyName: string, endpoint: string, method: string, body: any = {}, query: IDataObject = {}): Promise<any> { // tslint:disable-line:no-any
+
+	const returnData: IDataObject[] = [];
+
+	let responseData;
+
+	body.results_per_page = 200;
+	body.page = 1;
+
+	do {
+		responseData = await paddleApiRequest.call(this, endpoint, method, body, query);
+		returnData.push.apply(returnData, responseData[propertyName]);
+	} while (
+		responseData[propertyName].length !== 0
+	);
+
+	return returnData;
+}
+
+export function validateJSON(json: string | undefined): any { // tslint:disable-line:no-any
+	let result;
+	try {
+		result = JSON.parse(json!);
+	} catch (exception) {
+		result = undefined;
+	}
+	return result;
+}