✨ Add PostHog Node (#1440)

* ✨ PostHog Node

* ⚡ Minor improvements to PostHog Node

Co-authored-by: Jan Oberhauser <jan.oberhauser@gmail.com>

packages/nodes-base/nodes/PostHog/IdentityDescription.ts

@@ -0,0 +1,113 @@
+import {
+	INodeProperties,
+} from 'n8n-workflow';
+
+export const identityOperations = [
+	{
+		displayName: 'Operation',
+		name: 'operation',
+		type: 'options',
+		displayOptions: {
+			show: {
+				resource: [
+					'identity',
+				],
+			},
+		},
+		options: [
+			{
+				name: 'Create',
+				value: 'create',
+			},
+		],
+		default: 'create',
+		description: 'The operation to perform.',
+	},
+] as INodeProperties[];
+
+export const identityFields = [
+
+	/* -------------------------------------------------------------------------- */
+	/*                                 identity:create                            */
+	/* -------------------------------------------------------------------------- */
+	{
+		displayName: 'Distinct ID',
+		name: 'distinctId',
+		type: 'string',
+		required: true,
+		displayOptions: {
+			show: {
+				resource: [
+					'identity',
+				],
+				operation: [
+					'create',
+				],
+			},
+		},
+		default: '',
+		description: `The identity's distinct ID.`,
+	},
+	{
+		displayName: 'Additional Fields',
+		name: 'additionalFields',
+		type: 'collection',
+		placeholder: 'Add Field',
+		displayOptions: {
+			show: {
+				resource: [
+					'identity',
+				],
+				operation: [
+					'create',
+				],
+			},
+		},
+		default: {},
+		options: [
+			{
+				displayName: 'Properties',
+				name: 'propertiesUi',
+				type: 'fixedCollection',
+				placeholder: 'Add Property',
+				default: {},
+				typeOptions: {
+					multipleValues: true,
+				},
+				options: [
+					{
+						displayName: 'Property',
+						name: 'propertyValues',
+						values: [
+							{
+								displayName: 'Key',
+								name: 'key',
+								type: 'string',
+								default: '',
+							},
+							{
+								displayName: 'Value',
+								name: 'value',
+								type: 'string',
+								default: '',
+							},
+						],
+					},
+				],
+			},
+			{
+				displayName: 'Message ID',
+				name: 'messageId',
+				type: 'string',
+				default: '',
+			},
+			{
+				displayName: 'Timestamp',
+				name: 'timestamp',
+				type: 'dateTime',
+				default: '',
+				description: `If not set, it'll automatically be set to the current time.`,
+			},
+		],
+	},
+] as INodeProperties[];