Make ScaleOptions configurable

[yojagad]

Right now we have NumberOfSamplesToConsider defaulting to 5 and TargetQueueLength at 100 and these aren't configurable. Even if we do make this configurable, these values applies only to runtime driven scaling and customers on consumption plan might get confused. Might need to figure out a way to consistently introduce this to all extensions including RabbitMQ.

cc: @mathewc @pragnagopa @cachai2 @fabiocav @jeffhollan @paulbatum