[Feature Request]: Allow disabling sidebar tabs, topbar menu items, setting panels, etc. via hidden settings

### Is there an existing issue for this?

- [x] I have searched the existing issues and checked the recent builds/commits

### What would your feature do ?

There are many orgs deploying ComfyUI_frontend as part of a service. They want the ability to disable certain functionalities when serving the client view. For example:

- they may want to use their own internal workflow storage/sharing system and therefore disable the workflow sidebar
- they may want to disable topbar menu items to prevent saving things to comfy instance disk
- they may want to disable opening settings or changing hotkeys to prevent workarounds

See examples: https://www.seaart.ai/workflow, https://tensor.art/workflow

### Proposed workflow

1. Create hidden settings that offer easy way to configure which commands, sidebar tabs, topbar menu items, settings panels, settings, etc. are disabled
2. If something is disabled, prevent the associated UI components from loading and also prevent it from being loaded via workarounds e.g., using commands

### Additional information

_No response_

┆Issue is synchronized with this [Notion page](https://www.notion.so/Issue-3388-Feature-Request-Allow-disabling-sidebar-tabs-topbar-menu-items-setting-panels-et-1d16d73d365081f2974affd9938fb7cc) by [Unito](https://www.unito.io)