Break circular dependencies "qt/bantablemodel -> qt/clientmodel -> qt/bantablemodel"
Note that a dependency on QLocale was introduced in D8492. This PR seems to break whatever implicit include path that made QLocale available, so it needs to be included explicitely.
This is a backport of Core PR18036 [1/2]
Commit 61eb058cc10592cfa314ba2209fb370706100e8b