[Feature Request] Provide a function of 'free all CompletionItem'

[PisecesPeng]

Context

• This issue is not a bug report. (please use a different template for reporting a bug)
• This issue is not a duplicate of an existing issue. (please use the search to find existing issues)

Description

Hi👋!
I'm writing a custom language completion in my project,
it's dynamically registered via monaco.languages.registerCompletionItemProvider() in a different place.
Sometimes,
I wanna be able to have a function that 'free all CompletionItem for the specified language',
or, a function that 'override the CompletionItem of the specified language',
instead of using registerCompletionItemProvider:IDisposable().

Maybe only I need 😅.

Perhaps, such a method has been provided,
but I didn't find it, please let me know 😂.

Thanks!