Returns the plan set proposed by the renewal request attached to the given company contract, with pricing as of the renewal's date. If companyContractId is omitted, the current (or most recently created) company contract is used. Empty list if no renewal request exists for that contract.

Note: plan IDs returned here may differ from the plan IDs on the current company contract. During renewal, products can be updated or upgraded (e.g. a newer version of the same tier or a different product line), so the renewal plan set is computed independently and is not guaranteed to overlap with what is currently sold on the source contract.