Introduce global dictionary message direction

[christophd]

Global data dictionaries apply to all messages that get exchanged regardles of message direction inbound or outbound. In almost no cases a dictionary is able to be applied to both inbound and outbound messages.

Outbound messages may need dynamic field value generation while inbound messages may want to use variables, ignore element expressions and validation matchers.

Introduce message direction INBOUND/OUTBOUND for dictionaries so global scoped instances can decide which message to apply to.