MODE-1930 DDL Parser Should Use JCR Substitution Characters When Creating A Node With A Name Containing Illegal JCR Characters

Changed AstNode so that it knows how to convert name to valid JCR name. Changed DdlSequencer to use the JCR name of the AstNode when creating JCR nodes. If a ':' is found in the name, if the characters before the ':' is not a registered namespace prefix, then the ':' is made part of the name and the appropriate substitution character will be used.