BUG: display of dropdowns/lookups in tabs

There is a display bug for the add-/view- buttons next to dropdowns when applying field.dropdown().fix() on fields placed in tabs. The reason is that select2 dropdown container returns height = 0 in certain scenarios when applying the fix. Additionally there is an inheited css style for overflow-x which may hide the add-/view- buttons in certain sizing-scenarios. This bug will be fixed in next version which will be released probably in July 2020. We are sorry for any inconvenience! Refers to: