Implement numerical conversion for map's key or value


git-svn-id: https://root.cern.ch/svn/root/branches/v5-34-00-patches@49007 27541ba8-7e3a-0410-8455-c3a389f83636
std::pair also have implicit rules, so always craete a SchemaRuleSet


git-svn-id: https://root.cern.ch/svn/root/branches/v5-34-00-patches@49008 27541ba8-7e3a-0410-8455-c3a389f83636
Implement the implicit rule for matching pair (based on being able to convert their content


git-svn-id: https://root.cern.ch/svn/root/branches/v5-34-00-patches@49009 27541ba8-7e3a-0410-8455-c3a389f83636