support for local characters parsing values from strings

A cli user complained a DMR value created from a string like "jdbc:h2:file:${jboss.server.data.dir}/ô/h2/soa;mvcc=true" has local characters replaced with '?', i.e. "jdbc:h2:file:${jboss.server.data.dir}/?/h2/soa;mvcc=true".

There is a workaround for this in the CLI, though, for simple string values. If the parameter/argument value is not quoted then they are not parsed ModelNode.fromString(value) and the operation/command will succeed. But if this value is a part of a more complex DMR type then it will fail.