Sled Agent Cleanup: Specify types when setting SMF properties

https://github.com/oxidecomputer/omicron/blob/9700d4491909d9e4fc49677967b98e055840d963/sled-agent/src/smf_helper.rs#L66-L84

When the sled agent sets properties within zones, it uses a form of svccfg that omits types. This means that sled agent implicitly assumes the service (though the XML file, most likely) already has that property.

This isn't always true. As one such example, the tfport.xml and tfport-sofnpu-standalone.xml files got out-of-sync, and a property existed in one, but not the other.

If we forced callers to specify the type, we would:

1. Be able to add properties that don't necessarily exist,
2. Be able to validate the type, such that "if it disagreed with an existing property" we would throw an error.

Note: This is cleanup, and may be less relevant with the addition of self-assembling zones, as those should generally obviate the need to explicitly reach into zones and set properties.

Start in sled-agent/src/smf_helper.rs at lines 66-84 and trace the callers that set SMF properties within zones. Specify property types at the call boundary, then ensure new properties can be added and conflicting types are rejected. The issue does not name tests, so inspect the existing SMF helper coverage before validating the change.