fix: correct mcap channel name for OSI SV

When visualizing the OSI SV in Lichtblick, the channel name is "ConvertedTrace" which does not reflect the content of the channel.

Edit: Renamed the channel again slightly to match our topic name, so the settings in Lichtblick e.g. for the raw message panel don't have to be changed when switching between gt-gen-core trace and test traces: