C2MS12 — Make ME1 Optional for all Request Messages

Allow ME1 (DESTINATION-COMPONENT) to be optional in all request message subjects. Note that the Header field DESTINATION-COMPONENT is already optional in the message itself. This would be the same we do on the OMG Generic Service Request in C2MS12-22, and we don't need SERVICE-GROUP/NAME/OPERATION-NAME, because the rest of the C2MS Messages are typed and already carry what is being requested.

This is backward compatible, because it's moving ME1 from Required to Optional (less stringent).

Note, too, that there was already a sort of hint at this in section 6.2.3.5 Miscellaneous Elements of the C2MS Subject Name which in its final paragraph talks about possibly using ME1 not for DESTINATION-COMPONENT, but for "group names" as a way to indirectly reach a component that is part of a single grouping of services. That's a bit of a kludge, but just allowing it to be not-specified works great. As it turns out, "group name" isn't needed because the request message is already strongly typed (I need MVALS for domain1, domain2, mission, constellation, satellite). That's very specific already, and leaving ME1 blank allows requestors to put out this message with no known component name, but to get back a response of exactly what I asked for.