Problem: When CREATE/ALTER/DROP DATABASE statements are getting filtered
         out on slave because of the replication filters installed,
         server is not adding their GTID_EXECUTED to GTID_EXECUTED_SET.

Analysis: When ever a statement is getting filtered out due the filter
rule, server adds the gtid of the filtered transaction to GTID_EXECUTED_SET
by executing an empty transaction on the slave. So that the same transaction will be replicated again in case of
re connections and also GTID_EXECUTED_SET will not have any GAPS.
But this is *not* happening in case of three statements that are
mentioned in problem description (CREATE/ALTER/DROP DATABASE).

Fix: Code has re factored to make sure that an empty transaction
will be executed for these three statements (CREATE/ALTER/DROP DATABASE)
also.