Display processing bar when saving database in background

[jobe-m]

When the database is saved in background after editing an entry a processing bar should be shown.
Currently it is not visible that something in background happens.
Also the entry page will be updated after saving of the database is finished to avoid updating page entries if saving was not successful.

Location where to trigger the processing bar:

ownkeepass/common/src/keepassPlugin/databaseInterface/private/Keepass2DatabaseInterface.cpp

Line 590 in d251478