Enhancement: Allow option to customize which features show in the WP Admin sidebar

### Impacted plugin

Jetpack

### What

Allow option to customize which features show in the WP Admin sidebar

### How

Not sure of the best way to go about that.

If a Jetpack feature is deactivated, it would make sense that the option doesn't show in the sidebar. That's how it behaves for **Forms**, but not **Search**. But which behavior is actually expected?

A user also request to hide **Activity Log** and **Jetpack Manage**, but those don't have an option or module to toggle on/off.

Customer report: 10632520-zd-a8c

The issue names no files, tests, or entry points. Start by locating Jetpack's WP Admin sidebar and comparing how Forms and Search reflect feature activation, then clarify the expected behavior for Activity Log and Jetpack Manage. Done means an agreed customization option with consistent sidebar visibility rules.

Written by the indexing model from the issue text.