Add ClearUsage param to SubscriptionItemParams

[eclipse1985]

Accoring with the documentation, we need a ClearUsage parameter.

Right now is not possible to delete subscription items due to error:

Error encountered from Stripe: {"status":400,"message":"When deleting the subscription item ITEM_ID with a metered plan, all related usage records must be cleared too by setting clear_usage=true.","request_id":"REQ_ID","type":"invalid_request_error"}

[remi-stripe]

@eclipse1985 Thanks a lot for doing the work here!

[remi-stripe]

Released in 55.1.0