DateProvider.cs is not being used, removed it

Dateprovider class was removed
TransactionDate and related tests removed

TransactionDate was not being used in the code so removed it
Revert "DateProvider.cs is not being used, removed it"

This reverts commit 6019af2b502fe7053528fa8af15138562b58a9cb.
Revert "TransactionDate and related tests removed"

This reverts commit 0ff8189b289fcf784e0655f0ddd900c2e5e3f843.
getFirstCustomer

getFirstCustomer is not required and no requirement mentions that.