feat(editor, core): Integrate PostHog (#3865)

* Integrate PostHog - Part 1: Groundwork (#3753)

* Integrate PostHog - Part 2: Event capture (#3779)

* Integrate PostHog - Part 3: Session recordings (#3789)

* Integrate PostHog - Part 4: Experiments (#3825)

* Finalize PostHog integration (#3866)

* 📦 Update `package-lock.json`

* 🐛 Account for absent PH hooks file

* ✨ Create new env `EXTERNAL_FRONTEND_HOOKS_FILES`

* ⚡ Adjust env used for injecting PostHog

* 🐛 Switch to semicolon delimiter

* ⚡ Simplify to `externalFrontendHookPath`

* Refactor FE hooks flow (#3884)

* Add env var for session recordings

* inject frontend hooks even when telemetry is off

* allow multiple hooks files

* cr

* 🐛 Handle missing ref errors

* 🔥 Remove outdated `continue`

* 🎨 Change one-liners to blocks

* 📦 Update `package-lock.json`

Co-authored-by: Ahsan Virani <ahsan.virani@gmail.com>

packages/cli/test/unit/Telemetry.test.ts

@@ -1,7 +1,7 @@
 import { Telemetry } from '../../src/telemetry';
 import config from '../../config';
 
-jest.spyOn(Telemetry.prototype as any, 'createTelemetryClient').mockImplementation(() => {
+jest.spyOn(Telemetry.prototype as any, 'initRudderStack').mockImplementation(() => {
 	return {
 		flush: () => {},
 		identify: () => {},