mapistore/oxio: Let OxioConnect object to resolve column numbers to properties

This way we are going to have similar behavior no matter how
Messsage has been fetched using oxio api - either through
list messages or through get message
mapistore/python: Remove hardcoded password from backup/restore scripts
mapistore/python: Delete commented out code
mapistore/python: Clean extra pass-es - not needed anymore