Implement UDF functions for Point-in-time Recovery in PXC operator

Next UDF functions are needed for implementing Point In Time Recovery for PXC in our k8s operator.

GTID Set by binlog file name
The method that accepts a binlog file name and returns all GTIDs which are stored inside the binlog file that passed to the method.

For example:

$ getGTIDSetByBinlog(“mysql-bin.000002”)
$ 11ea-b9a7:7,11ea-b9a7:8

Binlog file name by GTID Set
The method that accepts a set of GTIDs and returns the name of the oldest binlog file which contains at least one GTID that was passed to the method and all GTIDs which are stored inside the returned binlog file.
 
For example: 

$ getBinlogByGTIDSet(“11ea-b9a7:10,11ea-b9a7:11”)
$ mysql-bin.000003/11ea-b9a7:9,11ea-b9a7:10,11ea-b9a7:11,11ea-b9a7:12