Update the code examples according to the latest project changes

[lovtsovaik]

• Documentation version: 7.2
• Link: https://doc.cuba-platform.com/restapi-7.2/#rest_api_v2_ex_get_entities_list

It is necessary to update all examples with a new CUBA version and new data model in the test project https://github.com/cuba-platform/sample-sales-cuba7

Main points:

• use _ instead of $ symbol in an entity name (see also the issue https://github.com/cuba-platform/restapi-docs/issues/18)
• update the data model in the queries and responses (OrderItems -> OrderLines, the Product entity inside of this item contains fields price and name, number and description does not exist)
• update the queries inside services ()
• update the result of the creation query according to the last changes described in https://github.com/cuba-platform/restapi/issues/28 and add the information about the responseView method parameter