[INTERNAL] sap.m.ComboboxBase: improves scroll calculation precision

- improves scroll calculation precision of the private .scrollToItem()
method, handle the paddings and borders of items

Change-Id: I8876113638baf8622a4e206e133cddd675da2027
[INTERNAL] sap.m.Select: improves scroll calculation precision

- improves scroll calculation precision of the private .scrollToItem()
method, handle the paddings and borders of items

Change-Id: I08775f41a8ad7a42d5d9e0b697235d20936bdd6b
Merge "[INTERNAL] sap.m.Select: improves scroll calculation precision"
Merge "[INTERNAL] sap.m.ComboboxBase: improves scroll calculation precision"