RankingOrder type 
Defines values for RankingOrder. 
KnownRankingOrder can be used interchangeably with RankingOrder,
this enum contains the known values that the service supports.
Known values supported by the service
BoostedRerankerScore: Sets sort order as BoostedRerankerScore 
RerankerScore: Sets sort order as ReRankerScore
type RankingOrder = string