HP-682 Feat/multiple paymodels

[mfshao]

Jira Ticket: HP-682

New Features

• Added new endpoint /allpaymodels to return information about all the paymodels the user have (in both hatchry config and dynamodb) as an array named all_pay_models, as well as the currently actived paymodel information of this user as a section named current_pay_model
• Added new endpoint /setpaymodel to set a new current_pay_model for the user

Improvements

• More paymodel information will be returned from Hatchery

Breaking changes

• In pay model configs, name has been changed to workspace_type
• In pay model configs, aws_account_id has been changed to account_id
• In pay model configs, ecs has its type changed from string to bool
• In pay model configs, vpcid has been removed