173 route for kds graph

[Xantass]

Describe your changes

add new route for get data of orders send

How to test the feature

call the route 'ordersCount' and check the return data

Issue ticket number and link

Closes #173

Checklist before requesting a review

• My code follows the style guidelines of this project
• I have commented my code, particularly in hard-to-understand areas
• I have performed a self-review of my code
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Documentation has been updated as required
  If a single item in this checklist is not checked, the pull request cannot be accepted

[JulesGresset]

You can't use clientCounts because it only counts 'Sur place' orders, in this case we want to be able to display the number of orders whatever their channel
+ missing documentation and confilct