* feat(core,schema,connectors): remove target,platform form connector schema and add id to metadata
* feat(schema,ui,console): unwrap ConnectorMetadata in ConnectorDTO
* feat(schema,ui,console): connector id use dashline instead of underscore
* feat(connector-alipay*): fix typos
* feat(connector-alipay*): remove unnecessary type declaration
* feat(connector): connector queries and APIs
* chore(connectors): remove type from DB schema design and fix code accordingly
* chore(connectors): put connector as ConnectorInstance's property
* chore(connector): put connector as optional property of ConnectorInstance