Define a structure for dealing with the geographic location of nodes.
Implement VerifyAndUpdate (with the same purpose as NodeValidator interface)
that checks LOCODE attribute and fills other attributes of the location.
Technically the entity is a wrapper over the NeoFS location database: it
maps the node LOCODE to the database record from which the new attributes
are generated.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>