[FIX] Field: clear invalid input and error for unit/currency
[FIX] Field: clear invalid input and error for unit/currency

on binding context change.

Change-Id: I743244a410f09fd0245c2530713f78e0a1c4550d
BCP: 2180165885
SAP/openui5,SAP/openui5,SAP/openui5,SAP/openui5