Auto fill limit orders with suggested limit price

Some users expressed confusion with which limit price to choose - we could autofill the price field with a suggested limit price similar to Robinhood to help mitigate


<img width="1079" alt="107594595-25192180-6bc7-11eb-8e58-9c396bdd6aa2" src="https://user-images.githubusercontent.com/13340486/127762622-eadb60af-4d29-49d9-a544-a6c01f37cd9b.png">
