MULE-7497: Add Oracle configuration for database connector

_ Updating oracle config element to enable configuring the datasource using separated attributes
_ Updating AbstractqueryMetadataProvider to return default type for each input parameter when there is no available metadata
_ Updating StatementResultIterator to manage resultsets returned as output parameters
_ Deleting all Oracle custom classes which are not required now
_ Updating tests and test databases to work with oracle if possible
Merge pull request #565 from mulesoft/MULE-7497

MULE-7497: Add Oracle configuration for database connector