Add configuration item to the Analytics submenu - pending user feedback.

Problem to solve

For Product Analytics, we need to introduce several new screens for the user to interact with. This includes approximately five screens for dashboards, query building & configuration, and cluster configuration settings, and funnel analysis, at a minimum. These screens need to be reachable via the left sidebar while also complying with our design and product guidelines.

For the experimental phase we introduced these screens to the General -> Settings area in Create configuration screen for configuring pro... (#403044 - closed). Pending user feedback we may want to move these for easier access.

Proposal

• Get approval on Left Nav change - see handbook reference
• Add a new Configuration item to Analytics submenu
• This is where Product Analytics configuration (Jitsu/ClickHouse/Cube.dev) will go
• Any additional configuration screens needed for new dashboards or features will go here

Implementation plan

backend - 2️⃣

1. Add new item declaration to add the item to configure_menu_items.
2. Create new method to add the new item if the feature is available for the project.
3. Update the specs to validate the menu item is shown accordingly.