Add mechanism for rulesets to add their own menu items to the editor …

[minetoblend]

Prerequisite to #35700

Adds an API for rulesets to add their own menu items to the editor menubar.

Since at the creation of the menu items access to DI is needed (i.e. to get ahold of a ConfigManager), the RulesetEditorMenuBarItems class extends from Component and is added as a child to the Editor.

[minetoblend]

This was split it out from the linked pr so I guess it's a prerequisite, updated the pr description.