(RTM-7593) Start new sale button

After completing a sale the user is shown a view of completed payment and information to start a new sale by scanning an item. 
Besides scanning a new item, user can press the text at the top of the view saying "Add item to start new sale" to start a new sale. 

(RTM-7630) Configuration for sending digital receipts

Setting if user should be shown the option to send digital receipts or not is based on the configuration for "SkipSendingReceipts" in Mobile POS Management. 
This is not set on member level, so if the button "Send receipt" is shown is based on if the value is set to "Never" or "Ask Cashier".

(RTM-8108) Cancel sale in test environment

Canceling payment for Coopay, when there is no camera available, Mobile POS was not moving back to choosing payment view as expected. 
If canceling a payment with no camera available user is now moved back to choose payment view. 

(RTM-7780) New test slot

To optimize the internal testing process, an internal test slot has been created that allows APKs to go directly towards this test slot. Therefore, Mobile POS can be tested internally without being released to Test- or Production environments. Testing in an environment not available to customers can improve test, security regarding tests and speed up test results.