Add checkboxes to enable the SDKs on the settings page

Problem/Motivation

Add a checkboxes form element to enable the

• JavaScript: https://posthog.com/docs/libraries/js
• PHP: https://posthog.com/docs/libraries/php

SDK integration on the module general settings page.

We should then put the dedicated settings per SDK into a vertical tabs group. The general settings that both share, can go into "General" tab.

Steps to reproduce

Proposed resolution

Remaining tasks

User interface changes

API changes

Data model changes